City of MilwaukeeDepartment ofNeighborhoodServices

W W W. C I T Y. M I LWA U K E E . G O V / D N S

Common ProblemsThis brochure only covers stairs for one and

two-family homes. Commercial buildings haveanother set of rules to follow.

A permit is required if you are replacing stairs.No drawings or plans are required, but it wouldbe helpful to know the height and run of thestairs. A short description of the project will belisted on the permit.

On stairways with more than 3 risers, onehandrail is required for the full length of thestairway on any open side and on the left, as onemounts the stairs. Handrails shall be located atleast 30" but not more than 34" above the nosingof the tread. Observe the 4” and 6” sphere rulesstated earlier.

Guardrails are required if the porch or platformis more an 24" above the floor or grade. Bothshall be at least 36" high and balusters spacedas to prevent the passage of a 6" ball. Both mustsustain a 200 lb. load applied in any direction.Every stairway shall measure at least 3 feet inwidth. Trim and handrails may project no morethan 3 1/2" into this width.

Any time the structural members are repairedor replaced a permit is required. Any electrical orplumbing work also requires a permit.

Biggest MistakesThe biggest mistake in building stairs is not

keeping ALL the steps the SAME height. Mostoften the first and last step are incorrect. Treadwidths and riser heights may vary in uniformityby a maximum of 3/8". However, the 8"maximum rise and 9" minimum run must bemaintained. Depending on your type ofoccupancy, landings may be required at certainintervals. Check with a code offical before youbuild.

Questions?For more stair building information talk to your

construction inspector. If you need moreinformation about permit requirements, fees, oryou just want to ask a “what if” question, call theDevelopment Center’s Permit Desk at 286-8210.Business hours are 8:00 A.M. to 4:30 P.M.

STEP FIVE: Make cut to fit porch

The cut may vary to attach the stair, however the7" rise is always maintained. Cut the wood so thetread is against the porch sill. Anchor securely.

STEP FIVE: Making the floor top tread

If you decide you want your floor to be the toptread follow these changes. Measure theheight of your vertical to include the floor,subfloor, carpet to the finished height. Sotypically 3/4" for the flooring above the joistsand 1/2" for carpet. Subtract this from the topriser height and cut to maintain the 7" stepfrom the last tread to the finished floor level.

5 Easy

Steps toBuilding

Stairs Correctly

DNS-107 STEPS BRO V5a TNW 160831

Secure the stringer to the porch.

7"

7"

7"

7"

7"

7"

5 1/2"

Cut

Finished stringer.If top tread iseliminated substract tread height (1 1/2”) plus flooring dimension,cut and secure toporch maintaining constant 7" rise with each step.

Porch sill(edge on view)

7"

For One and Two FamilyDwellings Only

7"

7"

7"

7"

CONCRETE SLAB

If you’ve done your math right, each step willbe 7" and even with the floor level you tookyour measurement from. TIP: If you are off ona step try shimming to maintain no more than3/8" variation. Do not exceed 8". Seeuniformity code information listed earlier.

Other Tips and Tricks

If your material is splitting, predrill your holes.This can also help prevent squeaking in thefuture. Glue and nail to stop squeaks.

To tighten stairs add glue blocks at theunderside between the tread and riserintersection.

Another very important but sometimesoverlooked item is to seal the underside ofyour stair. This will prevent the stair fromsqueaking and warping.

If you haven’t f igured it out yet, pre-cutstringers or pre-built stairs from stores rarelywork and are a waste of money and time. Dothe math! Measure twice...cut once!

Cut off 1 1/2" Riser height

Cut and anchor to header board

Also if an open stair, a 6” ballCANNOT pass through the

triangle opening in the riser or through the

space above thetread, next to the

riser and under the guard rail

or handrail.

STEP ONE:Measure total rise

Example is for conventional stairs where toptread is equal to floor level. Determine thedistance you have to climb from the ground tothe porch. Use a level set on the top floor andmeasure down.

If there is a slope to the bottom surface,measure from the center of the stairway. Thisis where equal rise and run will be measured.

STEP TWO: Divide vertical rise by 7.

A comfortable step to climb is 7 inches.Determine the number of steps by dividingthe height (example 28") by 7. (28÷7=4) Yourstairs will have 4 equal 7" steps called risers.The code limits the maximum stepping heightto 8 inches and a minimum height of 4inches.

Otherwise, divide the total rise by 7. Thenround up to the nearest whole number. Thatwill be your total steps. Divide total rise by thetotal steps and that becomes your riser heightper step.

For example say a 31" total rise. First divide itby 7 to determine the number of steps.31÷7=4.42 Take the whole number of step(4), then divide it into the distance (31) again.31÷4=7.75 This means each of your 4 steps,or risers, will be exactly 7 3/4" high. Do notexceed 8 inches per step. DOUBLE CHECKyour math. Measure twice...cut once!

State Code Says Coom 21.04 says: Uniformity.1. Within a stairway flight, the greatest tread depthmay not exceed the smallest tread depth by morethan 3/8 inch and the greatest riser height may notexceed the smallest riser height by more than 3/8inch.

STEP FOUR: Nosing room on treads.

An 1 1/4" nosing is desirable on stairs. Theactual size of a 2 x 12 board is 1 1/2" x 11 1/4".Since you left a 10" tread cut, adding the 2 x 12as a tread leaves you with a 1 1/4" nosing. (11 1/4"-10"=1 1/4")

Tip: If carpeting stairs, round over the top edgewith a 1/2” round-over bit before installing tohelp the carpet bend over the sharp edge.

STEP THREE: Measuring for the cut

Once you know how high each step is, it's timeto figure out how far out the step will run. Acomfortable unit run or tread will be 10". TheCode minimum is 9". Treads should containsome overhang from the risers (called nosing).This avoids tripping while ascending the stairs.Desirable nosing should be 1" to 1 1/2" from theriser. Our example is 1 1/4". If adding a riser,measurement is the same since some amount isbeing added to tread and riser.

Protected or treated lumber is required forexterior stairs. Use a framing square prepare tomark a 2 x 12 board. A framing square is a rulerbuilt at a 90° angle and marked equally on eachedge. Marking the lumber on one side, use apencil to mark the rise (7") on one outside edgeof the square and the tread cut (10") on the otheroutside of the square. Always start with the firstriser and end with the top riser, and draw in thetop floor line. At this point it is helpful to count thenumber of risers so there isn't a layout error.

Alternate Layout: If using closed risers, it isbest to cut the riser the full height of the rise andbutt the tread up to it. This allows the tread to benailed through the riser making it stronger. Adjustthe math to subtract the thickness of the riserfrom the tread and cut accordingly.

(Example 28")Total Rise

DeckFlooring

Concrete slab or stone (not gravel)

Level

7"

7"

7"

This is calleda Riser. DO NOTEXCEED 8”.

2 x 12board

7"5 1/2"

10" 7"7" 10" 7" 10" 7" 10"

Using the framing square, mark all the cut lineson the lumber, times the number of steps youhave. Be sure to take the measurement on theoutside edge of the square and intersect thelines at the edge of the 2 x 12 lumber. Thecompleted board is called a Stringer. In ourexample the Riser boards will be 5 1/2" high bythe width of the stairs. (7-1.5 = 5.5)

7"cut

Nail through riserfor stronger step 7"

No greaterthan 8" butmore than 4"total height perstep.

Important!Cut bottom end of the stringer where it restson the landing (concreteslab). Compensate for the thickness of the stairtread (1 1/2" in ourexample) andthus maintain the 7”rise.

2 x 12stair tread

11 1/4"actual

dimension

11 1/4"

10"cut

1 1/4"nosing

11 1/4"

2 x 12

7"

Post

Stringer

Cut Line

Concrete slab

1 1/2"

1 1/2"

RUN

RISE

Proceed down the board marking out eachstep along the board. Here is our example.

Note: Open ended risers are allowed onexternal stairs, however no opening shall allowa 4" ball to pass through the riser. Another ruleapplies if adding handrails and guard rails tothe stairs. No 4" ball can pass through therails. Since our riser height in this example is 51/2”, we will need 1 1/2" blocking to close theriser gap.

6” dia.ball

The number of stringers required depends onthe width of the stairway. The type andthickness of the material of the tread requiresthe stairs to be built strong enough to support40 pounds per square foot live load plus theweight of the stairs. Consult a lumber guide forthe species of the material of your tread forthose numbers.

10"7"

Adjust layout ifinstalling riser first.Maintain equal steps.