Redwood Naturally elegant

1-800-862-4657www.BuyRedwood.com

RedwoodEmpireA Division of Pacific States Industries, Inc.

Certified Kiln DriedSiding Patterns andApplicationsRedwood is synonymous with qualityarchitecture. No other siding materialadds value to a home or commercialbuilding like redwood. The value ofredwood’s beauty is immediately appar-ent and the value of its long-lastingperformance is appreciated for decades.

Architects and builders specify redwoodwith confidence, knowing that exceptionalperformance is grown into every boardand that redwood will add value andsales appeal to their projects.

Redwood’s Total PerformanceRedwood’s performance characteristicsare unique among American softwoods.Its superior stability is especially suited tothe demands of siding applications. Itsfinish retention, weatherability, flameresistance and insulation properties make it ideal for virtually any project andeven the most extreme climate.

Dimensional Stability Test reports fromthe USDA Forest Products Laboratoryshow that redwood has less volumetricand tangential shrinkage than any otherdomestic softwood. This means thatredwood siding will lay flat and straightthroughout the life of the structure withminimal warping, cupping, checking andnail popping. With tighter joints, redwoodprovides better siding performance than other woods.

Finish RetentionRedwood has an open cellular structureand contains relatively little pitch orresins. This enables redwood to absorband retain all types of finishes better thanmost other woods. As a result, projectslook better over a longer period of time.Protective finishes last longer and workbetter. Refinishing is required less often.

Resistance to Decay and InsectsRedwood heartwood has grown-inresistance to decay and insects that ispresent throughout the lumber, not juston the surface. Wood exposed throughsawing, boring or nailing is as decay-resistant as the surface.

The CRA trademark is on products ofmember mills of the California RedwoodAssociation only and is an additionalassurance of quality.

Redwood grades are established by theRedwood Inspection Service in theStandard Specifications for Grades ofCalifornia Redwood Lumber. Properlygrademarked lumber will bear the RISmark. The RIS is the exclusive rules-writing agency for redwood lumber.

Quality redwood siding is available in the architectural grades: Clear All Heart,Clear, Heart B and B Grade.

Clear All Heart is a superior grade forfine sidings and architectural uses. It is all heartwood and the graded face ofeach piece is free of knots.

Clear is similar in quality to Clear AllHeart, except that it includes sapwood in varying amounts. Some boards mayhave one or two small, tight knots on the graded face.

Heart B is an economical all-heartwoodgrade containing a limited number oftight knots and characteristics notpermitted in Clear or Clear All Heart. It is graded on one face and one edge.

B Grade is an economical grade con-taining a limited number of tight knotswith sapwood accenting the heartwood.

Specifying Storage&HandlingGrainRedwood lumber has either flat or verticalgrain. Siding Is considered vertical grainwhen the annual growth rings form anangle of 45 degrees or more with thesurface of the siding. If the angle is lessthan 45 degrees, the siding is known as flat grain. Vertical grain siding pos-sesses enhanced dimensional stabilityand will hold paints and finishes betterthan flat grain.

Vertical Grain Flat Grain

SeasoningClear All Heart, Clear, Heart B and BGrade sidings are available Certified KilnDried for applications requiring minimalshrinkage and top performance.Redwood kiln dried to accepted stan-dards will include the words “Certified Kiln Dried” or the initials “CKD” in thegrademark on each piece or package ofsiding or be so specified on the invoice.

PatternsStandard redwood siding patternsinclude: bevel, rabbeted bevel, tongueand groove, shiplap, channel shiplap andV shiplap. Board and batten siding is laid up using standard size boards.

Pattern NumbersEach siding pattern has a pattern num-ber. To ensure delivery of the properproduct, the pattern number should beincluded on specifications and invoices.Pattern details are given in CRA’sArchitectural Guide and RedwoodPattern Book.

TexturesSurfaced sidings have a smooth, planedface, emphasizing the wood’s grainand color.

Saw-textured sidings have resawn facesproviding a rough textured appearancethat holds finishes extremely well.

Specifying Redwood SidingTo ensure delivery of the proper sidingproduct, the specifications shouldinclude: use, grade, grain, seasoning,pattern description and number, andsurface texture.

For ExampleRedwood lumber for 1exterior siding shallbe CRA-RIS grademarked redwood,2Heart B grade, 3mixed grain. 4CertifiedKiln Dried, 51x8 channel V shiplap,6pattern 785R, 7saw-textured face to be exposed.1Use 5Pattern2Grade 6Pattern Number3Grain 7Texture4Seasoning

In addition, the Installation section of thespecification should specify: non-corro-sive fastener materials, type and size;bearing and fastener spacing require-ments; water repellent application as ap-propriate, and field priming of cut edges.

Storage and HandlingRedwood siding and trim are qualityfinish products and should be handledwith care. At the job site, redwood sidingshould be kept completely under coverand off the ground. Water-proof cover-ings should allow air to circulate betweenthe covering and the siding. Keeping thesiding clean and dry will help to eliminatethe possibility of finish problems. Forprotection, redwood siding is now avail-able wrapped in moisture-proof paper atthe sawmill and it should not be un-wrapped until installation begins.

PrimingIt is recommended that a water repellentcontaining mildewcide be applied to allsurfaces of redwood siding beforeconstruction begins. This will inhibit themovement of moisture as well as mildewgrowth, two conditions which canseverely damage a finish coating. Whena clear, bleached or semitransparentfinish is to be applied later, a preliminarycoat of water repellent will protect against weathering and constructionstaining prior to final finishing. For bestperformance, special care should begiven to end grain; cut ends should becoated before installation. Redwoodsiding should always be back-primed. Factory priming or pre-finishing is highly recommended.

ApplicationGeneral Application InformationCareful attention to construction detailingis necessary to prevent moisture pene-tration into the siding and the wall cavity.Flashing over window and door headersand at other horizontal siding breaksshould be sufficiently sized, well placed,tightly anchored and sealed with caulk-ing. Thorough caulking of all joints with a non-hardening compound is important,particularly at the butt joints of shortlength siding laid vertically. High per-formance caulks such as polyurethane,polysulfide or acrylic latex are recom-mended for best results.

The lowest edge of siding should be atleast 6 inches off the ground to preventmoisture problems. It is particularlyimportant that end grain at the bottom of vertical siding be coated with waterrepellent. The use of a drip cap at thelower edge of the siding is recommended.

A water repellent building paper, with apermeability rating of at least 5 perms,should be applied over sheathing. This willhelp reduce water and wind penetration.

Note: There have been reports of prob-lems arising from the combination ofwood siding and rigid plastic foamsheathings. CRA advises caution.Request Redwood Technical Data SheetUsing Redwood Siding Over Rigid Foam Sheathing.

Annual rings Bark side Pith side

Measuring and CuttingAll butt joints must occur over a stud orsolid blocking. Be sure that siding fitssnugly against corner strips and trim.Mitered corners, sometimes used withthicker patterns, should be cut in a miterbox. Plain bevel siding requires a com-pound miter. Predrill nail holes for allends, especially mitered ends.

Using bevel cuts at a 45° angle (seeillustration) can minimize the appearanceof gaps if end shrinkage does occur.

Do not reduce CRA lap recommenda-tions as this can result in damage fromwind-driven water. Carefully observeexpansion clearance requirements for the siding pattern selected.

NailingNailing recommendations refer to nailingsiding to every stud or (for vertical cours-ing) each 2x4 blocking line, at not morethan 24 inches on center.

Selection of proper nails is important.Siding nails with annular-ringed shanksprovide the best holding power. All nailsmust be either stainless steel, aluminumor top-quality, domestic, hot-dipped gal-vanized. Electroplated galvanized nailsare not recommended. Poor quality nails will react with redwood’s naturaldecay-resisting extractives, and will causeunsightly stains.

Nails can be countersunk (not more than1/16 inch) or driven flush with wood sur-faces. Unfilled nail holes may not be par-ticularly noticeable where natural finishesare used as long as proper quality nailshave been used. At mitered corners, ornear the edge or end of a piece, pre-drillthe nail hole to avoid splitting the wood.Nails must be long enough to penetrateinto studs (or stud and wood sheathingcombined) at least 1-1/2 inches. Do notfasten siding to only composition orpressed fiber sheathing as those materi-als provide no nail-holding power.

Do not use staples for redwood siding.Staples do not provide adequate holding power and most are not corrosion-resistant.

Preventing Moisture Problems

Proper interior and exterior wall constructionprevents moisture problems. Building papershould have a permeability rating of 5 perms,the vapor barrier, a maximum of 1 perm.

Moisture is the largest cause of sidingand finish problems. Most problems canbe avoided if precautions are takenduring construction. Understanding thedynamics of wood’s reaction with mois-ture will be the builder’s best protectionagainst callbacks.

New energy-efficient construction tech-niques increase the amount of humiditywithin homes and commercial buildings.Efficient insulation, storm windows,weatherstripping, as well as heatingequipment and appliances that retainwarmth add to the build-up of interiormoisture vapor.

This invisible moisture is one of the leastunderstood and most troublesome

causes of structural and finish failures. Itmoves as invisible moisture vapor fromthe warm interior of the house toward thecold exterior. Vapor travels throughplaster, insulation and wood and maycondense into water as it approaches thecolder exterior surfaces of the sidewall.This can sometimes result in structuraldamage as well as siding cupping andnail popping. Water entering the sidingcan also cause finishes to blister, peeland discolor.

Vapor barriers are necessary to preventmigration of moisture vapor. They mustbe applied to the warm side of the studwall, directly under the finish material.There are several types; the most fre-quently used are either plastic or alu-minum sheet material with a rating of one perm or less. Those sheets shouldoverlap at least 2 inches at their edges.Ordinary building felt is not a vapor barrier.

When residing an existing house withouta vapor barrier, an effective solution canbe to paint the inner side of the exteriorwalls with a vapor barrier paint.

Attic areas should be adequately ventedto prevent vapor from condensing on cold surfaces or penetrating through theceiling. Critical sources of humidity, suchas kitchens, baths and laundries, are best ventilated by fans that exhaust out-doors. Crawl spaces should be wellventilated all around the house; the ventarea should equal about 1/50th of totalfloor space. Keep vents free of obstruc-tions. Movement of vapor into studspaces from crawl spaces may takeplace as water evaporates from theground under the house, and can beretarded by laying polyethylene film over the ground. Basements may be asource of considerable dampness andrequire effective ventilation.

Bevel Cut Siding

StudSheathing

Stop MoistureFrom Outside

Siding FinishedOn All Surfaces

Sheathing

Building Paper

Stop MoistureVapor FromInside

Wallboard

Vapor Barrier

Insulation

Surface Feet of Bevel Siding to Cover1 Square (100 sq. ft.)

NominalWidth Plain Rabbeted

4 inch 160 128

5 inch 143

6 inch 134 117

8 inch 124 117

10 inch 122 113

Size AvailabilityBevel & Rabbeted BevelBevel

4'' 5'' 6'' 8'' 10''

1/2 inch • • • •3/4 inch • • •

Rabbeted Bevel S1S-2E smooth4'' 5'' 6'' 8'' 10''

1/2 inch • • •3/4 inch • • •

Rabbeted Bevel S1S-2E saw-textured4'' 5'' 6'' 8'' 10''

3/4 inch • • •

Bevel & RabbetedBevel PatternsRedwood bevel siding, also known as lapor clapboard siding, has the timelessappeal of a strong traditional style andprovides the deepest horizontal shadowline of all siding patterns.

Bevel siding is produced in both plain and rabbeted patterns. Each is availablein two different butt thicknesses forvariation in depth of shadow line andinsulation value.

Plain bevel patterns produce a boldershadow line than rabbeted bevel pat-terns of the same thickness. Rabbetedbevel, with its 1/2-inch rabbet milled to fit over the thin edge of the preced-ing course, allows the siding to lay flat against the studs or sheathing.Rabbeted patterns provide a weather-tight lap and lay up with greater coveragethan plain patterns.

AvailabilityBevel and rabbeted bevel sidings areavailable in all architectural grades.

Plain bevel siding has a smooth surfaceon one face and a saw-textured surfaceon the other face. Either face may beexposed. Rabbeted bevel siding isavailable with either a smooth or saw-textured face. Saw-textured faces aremore even in color and appearance andthey hold finishes better.

InstallationWith plain bevel patterns, use a furringstrip to support the lower edge of thestarting course. With rabbeted patterns,the bottom course should be supportedby a nailing strip sawn from the thin

edge of the pattern. Nail bevel siding atevery stud, which should not exceed 24inches on center.

For plain bevel siding, a lap of one inch isrequired to ensure weather-tightness.

Note: With CKD rabbeted bevel patterns,an expansion clearance of 1/8 inch isrequired in the rabbet.

Sample SpecificationExterior siding shall be CRA-RIS grade-marked redwood Clear grade, mixedgrain, Certified Kiln Dried, 3/4x8Rabbeted Bevel, pattern 372, with a saw-textured face.

Overlapundercourseby 1''

Stud

Sheathing

Beware of driving nail home with too heavy a final blow.Wood maysplit due to non-supportin cavity.

Nail clears tipof undercourse

Nail mustpenetratesolid wood 1-1⁄2''

1⁄8'' expansionclearance

Stud

Sheathing

Nail mustpenetratesolid wood1-1⁄2''

Plain BevelHorizontal Siding (Side View)

Rabbeted BevelHorizontal Siding (Side View)

Face nail with one nail only per bearing. Drive nail so shank just clears the tip of thepreceding undercourse. The space betweenthe nail shank and the tip of the precedingcourse should not exceed 1/8 inch.

Face nail with one nail only per bearing.Position material to allow expansionclearance of 1/8 inch. Drive nail about oneinch above lower edge of course.

Tongue & GrooveRedwood tongue and groove siding isversatile and weathertight. Its variety of refined patterns has established a permanent place in residential and commercial architecture. Tongue andgroove siding can be laid up vertically,horizontally or diagonally and is ideal formatched interior-exterior combinations.Tongue and groove patterns are pro-duced in square edge, eased (slightlyrounded) edge and various widths of V groove edges. The latter create ashadow line emphasizing the direction of the courses. Various design effects are achievable by alternating patternsand board widths.

AvailabilityTongue and groove sidings are availablein all architectural grades.

Standard tongue and groove patternscome from the mill with a smooth surfaceon both faces. Reversible patterns aresaw-textured on one face and surfacedsmooth on the other. All tongue andgroove siding patterns can be specialordered saw-textured. Saw-texturedfaces are more even in color andappearance and they hold finishes better.Tongue and groove redwood is alsoavailable in thinner patterns commonlyused for interior paneling.

InstallationTongue and groove siding is properlyapplied with the groove edge down; thisassures a weathertight wall.

Horizontally-applied tongue and groovesiding should be nailed at every stud, not exceeding 24 inches on center.Siding applied vertically should be nailedto 2x4 horizontal blocking that is

installed between the studs at not morethan 24 inches on center. As an alterna-tive, vertical siding may be nailed to 1x3furring strips and solid wood sheathing at24 inches on center.

Sample SpecificationExterior siding shall be CRA-RIS grade-marked redwood Clear grade, verticalgrain, Certified Kiln Dried, 1x8 Tongueand Groove, pattern 712R, saw-texturedface to be exposed.

Surface Feet of Tongue & GrooveSiding to Cover 1 Square (100 sq. ft.)Nominal Width Coverage Factor

4 inch 128

6 inch 118

8 inch 117

10 inch 113

Size AvailabilityTongue & GrooveEased Edge S2S-CM

4'' 6'' 8'' 10''

1 inch • • •

V1S S2S4'' 6'' 8'' 10''

1 inch • • • •

V2S-S1S Saw Textured 1S4'' 6'' 8'' 10''

1 inch • • • •

Stud

Sheathing

Blind nailed

Nail must penetratesolid wood1-1/2''

Stud

Sheathing

Nail must penetratesolid wood1-1/2''

Tongue and GrooveHorizontal Siding (Side View)

Tongue and GrooveHorizontal Siding (Side View)

Tongue and groove siding 8 inches or widershould be face-nailed, using two 8-pennynails per bearing.

For 4-and 6-inch widths of tongue and groovesiding over solid wood sheathing, blind nailingis possible using one 8-penny finishing nailper bearing.

Shiplap &Channel ShiplapRedwood shiplap patterns are widelyused for siding and paneling because of the varied visual effects that can beachieved. The boards are self-aligning,which makes installation easy. Shiplappatterns form strong, deliberate shadow lines.

Shiplap siding in V channel, Cove andBoston shiplap patterns can be appliedeither horizontally or vertically. Square-edged channel shiplap patterns shouldonly be applied vertically.

AvailabilityShiplap sidings are available in all archi-tectural grades.

Standard shiplap siding has a smoothfinish on both sides, except those pat-terns designated with the suffix R, whichare reversible. Those have a saw-texturedchannel pattern on one side and a smoothfinish V pattern on the other. Shiplapsiding patterns can be special orderedwith a saw-textured face. Saw-texturedfaces are more even in color andappearance and they hold finishes better.

InstallationShiplap sidings applied horizontally startwith the bottom course and are nailed ateach stud, which should not exceed 24inches on center. Channel shiplap pat-tern sidings require a 1/8-inch expansionclearance in each joint.

Shiplap siding applied in vertical coursesshould be nailed to 2x4 horizontalblocking that is installed between thestuds at not more than 24 inches oncenter. As an alternative, vertical sidingmay be nailed to horizontal 1x3 furringstrips and solid wood sheathing at 24inches on center.

Sample SpecificationExterior siding shall be CRA-RIS grade-marked redwood Clear All Heart grade,mixed grain, Certified Kiln Dried, 1x8 V Shiplap, pattern 794, smooth face.

Surface Feet of Shiplap Siding toCover 1 Square (100 sq.ft.)Nominal Width Coverage Factor

6 inch 124

8 inch 121

10 inch 116

Size Availability Shiplap Patterns

6'' 8'' 10''1 inch • • •

For 6-inch V Shiplap patterns, use one nailper bearing with the nailing point one inchfrom the overlapping edge. For patterns 8inches and wider, face nail with two sidingnails per bearing. Position nails one quarterthe width of the material in from each edge.

Stud

Sheathing

1⁄8'' expansionclearance

Nail mustpenetratesolid wood 1-1/2''

Stud

Sheathing

Nail mustpenetratesolid wood1-1/2''

Channel ShiplapVertical Siding (Overhead View)

V ShiplapHorizontal Siding (Side View)

Use one nail an inch from the lap for 6-inchChannel Shiplap. Face nail with two nails perbearing for 8-inch and wider patterns. Spacenails 1-1/2 inches from edge of overlap andtwo inches from edge of underlap for 8-inchboards. Nail wider patterns proportionately.

Board & BattenThe popular board and batten sidingstyles are not, strictly speaking, sidingpatterns but are created using standardsize lumber. Any number of interestingtreatments can be created, includingvarious width battens over wide board,even spaced board and batten, andreverse board and batten.

AvailabilityAny clear or tight-knot grade of redwoodlumber may be used, either with smoothor saw-textured face. Clear All Heart,Clear, Heart B and B Grade lumber isavailable Certified Kiln Dried.

InstallationBoard and batten patterns should only beapplied vertically. Boards should benailed to horizontal blocking placed notmore than 24 inches on center. As an alternative, 1x3 or greater horizontal furring strips may be applied over solidwood sheathing.

Sample SpecificationExterior siding shall be CRA-RIS grade-marked redwood, B grade, mixed grain,Certified Kiln Dried, 1x10 saw-texturedand 1x2 saw-textured battens.

Board and Batten SidingThickness Width

Nominal Surfaced Nominal Surfaced

2 1-1/2

1 11/16 3 2-1/2

1-1/4 1 4 3-1/2

2 1-1/2 6 5-1/2

8 7-1/4

10 9-1/4

12 11-1/4

Space underboards at least 1/2 inch apartand nail with one nail per bearing through thecenter of the material. For boards wider than8'', use two face nails evenly spaced. Widerspacing may be used with wider battens. Nail batten strips through the center so thenail shank passes through the space. Makecertain the batten laps the underboard at least 1/2 inch on both sides.

Board and batten siding can have a variety of appearances depending on the width ofboards and battens. A reverse board andbatten pattern is achieved by placing wideboards over the narrow battens.

Stud

Sheathing

Nail mustpenetratesolid wood1-1/2''

Board and BattenVertical Siding (Overhead View)

CaliforniaRedwoodAssociation

Redwood—our renewable resource

Additional LiteratureArchitectural GuideRedwood Pattern BookGrades and UsesExterior Finishes

FinishesRedwood FinishesApply finishes to clean, dry surfaces only.The optimum temperature range isbetween 50 and 70 degrees Fahrenheit.Saw-textured redwood holds finishes upto twice as long as smooth-surfaced wood.

Siding Finishes for Redwood Description Application Maintenance

Clear Water Repellents withMildewcideStabilize color at a buckskin tan and letthe grain and texture show through.Minimize the effect of weathering andredwood’s natural darkening.

Apply with brush or roller. Two coatsrecommended for new wood. Coat sawnends, backs and edges before nailingsiding in place.

Reapplication required after old finishhas lost its effectiveness. Reapplicationmay be required every 18-24 months.

Bleaching or Weathering StainsProvide a gray, natural weatheredappearance. Bleaches accelerate thenatural color changes of wood.

Apply with brush or roller. Use one ortwo coats according to directions.Bleaching action may be aided byperiodically spraying surfaces with water.

Bleaching stains provide low mainte-nance. Periodic reapplication of clearwater repellent with mildewcide isrecommended.

Semitransparent StainsVariety of colors are available in thesefinishes that let the wood grain showthrough. Oil-based stains are recom-mended for best performance.

Apply with brush for best results, rollernext best applicator. Two coats usuallyrequired for new wood; follow manu-facturer’s directions.

Color may wear away after weathering.Refinishing may be necessary every 2-4 years. Remove loose dirt and old finish with bristle brush before refinishing.

Solid Body StainsAvailable in a variety of opaque colors.These finishes obscure the grain andhave an appearance similar to paint.Latex stains should be applied over acompatible stain-blocking primer.

For best results apply with brush. Avoiddrips and lapmarks. Two coats usuallyrequired for new wood; follow manu-facturer’s directions.

Color may wear away with age.Refinishing may be necessary every 3-5 years. Remove loose dirt and oldfinish with bristle brush before refinishing.

PaintsDurable attractive finishes for traditionalexteriors. Paints obscure the grain andthe texture of the wood.

Apply with brush for best results. Rolleris next best applicator. One prime coat andtwo finish coats are recommended. Back-priming required. Use oil- or alkyd-resinbase primer and acrylic latex top coat.

Repaint one coat after most of old coathas weathered. Avoid creating an ex-cessively thick paint film. Sand or scrubwith bristle brush to remove old finishand dirt. Countersink nails if sanding.

Caution: Varnishes, lacquers and clearfilm-forming finishes deteriorate rapidlyin moisture and sunlight, so they shouldnot be used.

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818 Grayson Road, Suite 201Pleasant Hill, California 94523-2693Telephone 925-935-1499Toll Free 1-888-Cal-RedwoodFax 925-935-1496www.calredwood.org

Painting Redwood Siding:Guidelines to ExtendingMaintenance Cycles

Properly specified and applied paint systems perform better on redwood than on practically any other wood substrate. The USDA Forest Products Laboratory ranks redwood in the highestcategory among softwoods with regard to characteristics for painting and finishing.

For a long-term, low-maintenance service life, high quality paintsystems should be applied over the correct grades of kiln dried redwood on structures built with proper construction methods.While the initial cost for painting is higher than for application of natural finishes, the rewards are much longer maintenance cycles and higher levels of protection provided to the substrate.Most natural finishes require reapplication in from one to threeyears. High quality paint systems typically provide seven to tenyears of service.

Paint grades of redwood include Clear All Heart, Clear, Heart Clear, B Grade and Heart B. Sidings, trim and fascia can be solidboards or more economical finger-jointed or end- and edge-gluedlumber, and should be specified Certified Kiln Dried. Specify vertical grain for maximum performance. If flat grain lumber isused, install boards with the bark side exposed, as the grain of anyspecies tends to separate or “shell” on the pith side, rupturing thepaint film. Specify saw-textured surfaces on flat-grain products toreduce grain raising and improve overall paint performance.

Several keys to a high quality, long-lasting paint job are:

■ proper siding specification and construction practices,

■ proper surface preparation and priming,

■ the selection and proper application of high quality paint products

■ and, maybe most importantly, not taking any shortcuts.

Redwood ranks in the highest category for paintingand finishing…

Quality paint systems provide seven to ten years of service…

Painting Checklist

Siding Priming

Grade Oil- or Alkyd-Based

Moisture Content Coverage Rate

Grain Brush Apply

Texture or Factory Prime

Preparation Top Coat

Clean, Dry Surface Acrylic Latex

Proper Temperature Coverage Rate

and Weather Conditions Number of Coats

Pre-primed redwood offersconsiderable advantagesover job-site priming…

PrimingUse one coat of an oil- or alkyd resin-based primer for redwood.Backprime. Prime all ends, edges and sides. As an alternative to oil- or alkyd resin-based primers, use two prime coats of a water-borne “stain-blocking” primer specifically formulated for extractiverich woods. Work primers into the wood with a brush or roller, andallow to dry (according to manufacturer’s recommendation) prior tofinish coat application.

Do not allow wood to weather in an unprimed state. Weathering atthis time reduces the paint-holding quality of the wood surface. Ifsome weathering does occur, clean the wood surface and lightlysand to prepare it for priming and painting.

Protruding fibers on saw-textured surfaces act as channels for moisture, resulting in extractive staining. Brushing a minimum oftwo coats of primer into saw-textured surfaces assures a continuous,moisture-resistant film. Spray applications do not apply a continu-ous film on saw-textured surfaces, so they should be followed bythorough back-brushing or back-rolling.

Paint manufacturers recommend application rates for the primer interms of square feet of surface covered per gallon. These instruc-tions should be carefully followed. Some painters thin the primertoo liberally on the job to extend its coverage per gallon. Avoid thisas it reduces the capability of the primer to do its job properly.

If the siding has been prefinished with a paintable water repellentpreservative solution, prime it as you would bare wood beforeapplying the top coats.

Some redwood suppliers offer pre-primed sidings, trim and fascia. Pre-primed redwood has considerable advantages over job-site priming. High quality factory-applied prime coats can

Weathering reduces paintholding qualities…

Use brush application forsuperior results, especiallyfor first coat…

seldom be duplicated in the field. Factory application of primerscontrol two of the most important variables which determine paintperformance: the characteristics of the wood substrate and the qual-ity and application of the primer. The wood for factory priming iscarefully selected, handled and stored prior to priming to ensure aclean, dry surface on which to apply the primer. By controllingapplication rates carefully, the factory can apply an even primercoat of known thickness. The benefits of factory pre-priming makeit the preferred choice whenever possible.

When pre-primed material is cut during field application, the cutends should be field primed prior to installation. This frequentlyoverlooked step is very important since moisture moves much morerapidly through the end-grain than through the face of wood.

Factory pre-primed surfaces should be painted within 30 days ofinstallation, or dirt, moisture and chalking may prevent bonding andshorten the life of the paint film. If the primed surface is allowed toweather for an extended period of time, clean and reprime the surface prior to topcoat application.

TopcoatsUse two topcoats of a top-quality acrylic latex paint for redwoodsiding. Acrylic latex paints remain flexible with age, thus stretchingand shrinking with the wood and allowing some passage of watervapor. These characteristics prevent the cracking and blistering that sometimes occur with oil- or alkyd resin-based topcoats. Twoacrylic latex topcoats over an oil- or alkyd resin-based primer willoutlast both oil- and alkyd resin-based topcoats. Acrylic latextopcoats also perform well over water-borne “stain-blocking”primers and factory-applied primers.

Apply topcoats in warm, dry weather, not below 50 degrees F., towood that is clean and free of dust, dirt, grease and surface moisturefrom light rain or dew. The old painter’s adage, “follow the sun”should be heeded. This means paint any area after the sun haspassed overhead so that the sun’s rays do not strike the surface during or immediately after the painting. “Following the sun” givesa slower drying rate and a better paint film.

Finish coats or topcoats can be applied to broad surfaces by rolleror spray, but brush application is the superior application method,especially for the first coat. Research has indicated that the optimumthickness for the total dry paint coat (primer and two topcoats) is3.5 to 5.0 mils (1.0 mil equals 0.001''). To avoid future separationbetween paint coats, the first topcoat should be applied within twoweeks of the primer and the second coat within two weeks of thefirst coat.

Paint primed surfaces within30 days for maximum bonding and long life…

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CaliforniaRedwoodAssociation

Maintain painted surfaceswith washing and repaintingas necessary…

Maintenance and RefinishingPeriodic washing helps maintain painted surfaces. Repaint onlywhen the paint film erodes enough to show faded areas or wood-grain patterns. One coat is usually enough; paint film that becomestoo thick from repainting cracks across the grain and peels away.Where paint has eroded completely, siding should be repainted assoon as possible. After removing loose flaking old paint, sand andspot prime any bare wood prior to topcoating. If the paint showsevidence of moisture problems, don’t repaint until the source of themoisture is located and eliminated.

In areas of high humidity, mildew makes paint look dirty andsplotchy. To remove it, scrub with a solution of one cup of house-hold bleach in a gallon of warm water. Commercial mildew removalproducts are also available. Wear rubber gloves and rinse all surfaces with clear water after treatment.

Note: Household bleach should never be mixed with detergent containing ammonia. Fumes can be fatal!

Paint additives minimize mildew growth. Check paint containerlabels for mildewcide, or add it separately. These products, andadvice about their use, are available from paint suppliers.

Additional information on painting techniques is available frompaint manufacturers and dealers and from the following publication:

Finishes for Exterior Wood. Selection, Application andMaintenance. A comprehensive guide to the painting/stainingand maintenance of homes, decks, log structures, and more. 1996.Forest Products Society, Madison, WI.

818 Grayson Road, Suite 201Pleasant Hill, California 94523-2693Telephone 925-935-1499Toll Free 1-888-Cal-RedwoodFax 925-935-1496www.calredwood.org

Redwood—our renewable resource

Finger-Jointed and GluedRedwood Products

Finger-jointed and glued redwood lumber provides the performanceand quality of architectural grade redwood at an economical price.

It is ideal for fascia, soffits, siding and trim as well as for interiorpaneling and ceiling uses. Whether end-glued, edge-glued, or bothend- and edge-glued, finger-jointed and glued lumber is made fromsmall pieces of Certified Kiln Dried redwood that are precisionmachined and joined with an exterior adhesive cured by high frequency electrical energy. This process has been tested andrefined for over 30 years. It is an efficient technique that makes themost of the top quality wood in each log.

California redwood is classified by the U. S. Forest ProductsLaboratory as one of the woods that glues easily under a wide rangeof gluing conditions. In addition, the heartwood and sapwood takeand hold glue equally well. Redwood is easy to work with machinetools. This is important since good machining of the surface isessential in preparation for gluing, and since most glued redwood is machined after gluing.

Glued lumber is exceptionally straight and stable. It has the naturalstability of Certified Kiln Dried redwood, and because small piecesof joined lumber tend to be more stable than solid lumber, finger-jointed products stay flat, with minimum crook or cup.

Sizes and PatternsNominal thicknesses from 3/4 inch to 2 inches and nominal widthsfrom 2 to 12 inches are available. Wider panels are also availablefor special uses. Glued redwood lumber can be run to any standardCRA pattern with either a smooth or saw-textured surface. Single

Machining and joiningprocess uses efficient andprecise technique…

Order any standard patternwith either smooth or saw-textured surface…

End-gluedShort lengths are finger-jointed and end-glued only.

End- and edge-gluedPanels made up of randomwidth finger-jointed stockglued edge to edge.

Edge-gluedPanels made of full lengthstrips glued edge to edge.

Tec - 96/04

PDF 2011

CaliforniaRedwoodAssociation

Specify vertical grain foradded dimensional stabilityand finish retention…

Finish with paint or solid-body stain system…

and double plowed fascia are available. Since finger-jointed redwood is manufactured as a continuous board, it can be orderedin specific lengths up to 24 feet, depending upon the manufacturer.

GradesGlued redwood products are produced in the grades of Clear AllHeart, Clear and B Grade in accordance with the provisions of RISStandard Specifications for Grades of California Redwood Lumberparagraphs 211(a), (b) and (c). Vertical grain can be specified forenhanced dimensional stability and finish retention.

FinishingRedwood glued exterior siding, fascia and trim products are in-tended for uses where they will be finished with a paint or solid-body stain system (i.e. they are considered “paint grade” products).

The preferable finish system consists of a prime coat of oil- oralkyd resin-based primer followed by two topcoats of a top qualityacrylic latex paint. All ends, edges and sides should be primed.Factory prepriming is recommended. If the primer is allowed toweather longer than 30 days, the surface should be cleaned andreprimed prior to applying the topcoats. Any visible openings atglue joints should be filled with an exterior wood filler and sandedsmooth prior to topcoating.

Solid-body stains, either solvent- or water-borne, should be applied over a prime coat of oil- or alkyd resin-based primer. As analternative, two prime coats of a water-borne stain-blocking primerspecifically formulated for extractive rich woods may be used foreither paint or solid-body stain systems. The initial prime coatshould be allowed to dry thoroughly before applying the secondprime coat. Primer and topcoats should be compatible and preferably produced by the same manufacturer. Two topcoats ofsolid-body stain are recommended. Acrylic latex solid-body stainswill provide superior service.

Brushing or rolling is the preferred method of application. Spray application followed by back brushing or back rolling isacceptable. Closely follow finish manufacturer’s recommendationson application conditions and coverage factors. For further information on painting exterior redwood, refer to CRA TechnicalData Sheet Painting Redwood Siding: Guidelines to ExtendingMaintenance Cycles.

818 Grayson Road, Suite 201Pleasant Hill, California 94523-2693Telephone 925-935-1499Toll Free 1-888-Cal-RedwoodFax 925-935-1496www.calredwood.org

Redwood—our renewable resource

Pitch Bleeding in Redwood

Redwood injoys a reputation of being relatively free of pitch and resin. From time-to-time however, some minor pitch bleeding becomes evident when redwood is exposed to high temperatures such as when used for siding, trim or fascia on a south or west facing wall. Under conditons such as these, small, sticky gold colored globules of pitch may bleed to the wood surface. This pitch is not visually evident in the product during manufacture and grading. This bleeding is usually characteristic of the wood and may occur in redwood lumber which is properly manufactured, dried and graded. It is not considered a defect in the wood.

The pitch or resin can be easily removed with a clean rag and mineral spirits or turpentine. Most bleeding will subside after the initial exposure to elevated temperatures. If necessary, after cleaning, spot prime the locations with a primer specifically formulated for blocking pitch and resin such as KILZ or Zinsser Primer-Sealer, and refinish.