canadian supplement to certi radon mitigation...

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Center for Environmental Research & Technology, Inc.www.certi.us • 719-632-1215

Copyright © CERTI 2013

CERTI©

Canadian Supplement to CERTI Radon Mitigation Course

Everything you have learned PLUS!

Assumes you have viewed the Canadian Measurement Course Supplement

Center for Environmental Research and Technology, Inc.© 2013

CERTI©

What is Similar? Approach

Active Soil Depressurization

Ventilation

Common certification oversight National Radon Proficiency Program

Radon behavior Radon acts the same on either side of the border

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CERTI©

What are Basic Differences?

Measurement Units SI units

Active Soil Depressurization Fans can be inside living space

Discharges do not have to be above the eave

Radon Measurements Long-term test preference

CERTI©

Canadian Mitigation Guidance

Radon Entry

Mitigation Techniques

Worker Safety

Post-Mitigation Testing

Not specifically a radon standard

Local codes govern

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CERTI©

Radon Entry

Same factors cause entry of radon laden soil gases Emanation

Diffusion

Radon from water supply

Soil to interior pressure differentialsLargest factor

Wind

Stack effect – due to colder climate can be more significant in Canada than in lower 48 of U.S.

CERTI©

Radon in Water

No specified limit for radon in drinking water Low risk from ingestion

Outgassing can increase indoor radon levels

Actions to reduce indoor air contribution if radon in water levels are in excess of 2,000 Bq/L water

http://www.hc-sc.gc.ca/ewh-semt/alt_formats/hecs-sesc/pdf/pubs/water-eau/radiological_para-radiologiques/radiological_para-radiologiques-eng.pdf

May 2009

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CERTI©

Radon from Water Estimation

Rate at which radon outgasses is identical (Be careful of units)

Amount in Water Amount in Air Transfer Factor

pCi/L of Water pCi/L of Air

10,000 1 10,000 to 1

Bq/L of Water Bq/M3 of Air

370 37 10 to 1

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200 Bq/M3 air x 10 Bq/L water per 1 Bq/M3 air = 2,000 Bq/L water

Example: How much radon in water could yield 200 Bq/M3 in Air

CERTI©

Stack Effect

Increases as the outdoor temperature drops relative to a constant indoor temperature.

Vacuum or

Negative Pressure

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CERTI©9

Differential Pressure Measurements

English Units (U.S.)Inches of Water Column

SI Units (Canada)Pascals

Most instrumentscan measure in

either unit

1 pascal = 0.004 inches of water column

A thousandth of an inch is ¼ of a Pascal

You should use a micromanometer than read to 0.1 Pa

Switch

CERTI©

Stack Effect

We have to overcome Independent of HVAC

Function of: Building height

Outdoor temperature

Sources:

• CERTI RRNC Course

• Engineers Tool Box

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CERTI©

Canadian Guidance Table

Provides Estimate of Stack Effect

Reducing Radon Levels in Existing Homes: A Canadian Guide for Professional Contractors - 2010

CERTI©

Radon Reduction Approaches

1. Reduce Entry Eliminate foundation openings

Decrease pressure in soil beneath foundation (ASD)

2. Isolation and Ventilation Change air circulation patterns to intercept radon prior

to entering living space

Provide dilution air (Heat Recovery Ventilators)

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CERTI©

Buried Ductwork! Ductwork typically leaks

FAU: ON Buried returns – under

significant negative pressure Draws soil gases in through leaks

and dumps them inside


Buried Supply- Positive pressure when FAU is off• Low soil gas entry into ductwork• May depressurize house or force soil gas into home via slab openings

FAU: OFF

• Either buried supply or return provides pathway that interior negativepressures can draw radon in.

CERTI©

Sub-Membrane Depressurization (a)

Same approach as previously taught

Membrane Material 0.08 mm two ply laminated high density poly (~3 mil)

Laminated high density poly reinforced with polyester or fiberglass scrim.

Polyolefin reinforced with non woven textile

EPDM sheets (roofing material) up to 1 mm

Thicker material used if area to be used for storage Protective mats can also be used

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CERTI©

Sub-Membrane Depressurization (b)

Edges Run up 100-300 mm on walls (3-12 in.)

Caulked AND secured with battens secured with masonry fasteners

Seams Overlap 300 mm (12 in.)

Caulked

Reducing Radon Levels in Existing Homes:A Canadian Guide for Professional Contractors - 2010

CERTI©

Sub-Membrane Depressurization (c)

Penetrations Seal around

Collar of membrane material, or

Roof flashing

Drainage If water can accumulate on top of

membrane install trapped drain

Penetration Seal

Water drain that can be sealed tomembrane in low spot for water relief

Polyurethane caulkPoly sheeting

Roof Jack Approach

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CERTI©

Sub-Membrane Depressurization (d)

Soil Gas Collection can be improved with: Aggregate under membrane

Loop of perforated pipe under mat

Permeable mattingRadon System Piping

Ground Cover

Soil Gas Retarder

Soil Gas Collector

Sealed

Radon System Piping

Ground Cover

Soil Gas Collector

Sealed

SGC Mat laid under membranealso used under slabs in

new construction

CERTI©

Sub-Membrane Depressurization (e)

Fan Sizing Hard to do diagnostics before system installed

Experience will dictate

Degree of sealing plays large role

Similar air flow from SMD as from a sub slab system if edges reasonably sealed.

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CERTI©

Sumps and Drains

Closure of open sump (interior) and exhaust to outside should be one of first approaches.

Open drains should be fitted with Duck bill traps

Mechanical flappers

Water traps

CERTI©

Using Sump and Drainage Systems (a)

Sealing Sealing interior sump can help but will not prevent

radon from entering via other openings

Connecting ASD to drains Very effective in reducing radon from sump and other

foundation openings.

Can also beneficially impact hollow block walls

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CERTI©

Using Sump and Drainage Systems (b)

Sump Covers Bear weight of 70 Kg (150#) person

Fasten to floor

Seal with gasket or silicone (needs to be removable)

Insure water drainage not interfered with.

Label

CERTI©

Using Sump and Drainage Systems (c) Floor Drains

If drain to subgrade install drain traps

If drain to sump Insure 6 inch deep water trap, or

Install drain traps

If water on floor drains to sump Insure cover is flush with floor

Drain trap installed on cover

Investigate other drains A/C condensate drains

Ice makers, softeners, etc.

Reducing Radon Levels in Existing Homes:A Canadian Guide for Professional Contractors - 2010

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CERTI©

Using Sump and Drainage Systems (d)

Fan Sizing Hard to do diagnostics before system installed

Can temporarily install sump lid and connect vacuum cleaner or radon fan

Drill pilot holes to determine effective area

These are highly successful systems

Degree of sealing plays large role

Similar air flow from DTD as from a sub slab system if slab is reasonably sealed.

Systems that create more than 250 Pa (1 inch) W.C. may pull water through trapped drains

CERTI©

Using Exterior Perimeter Drains (a)

Impact Area HC Guidance suggests full loop is optimal

Be careful of downspout and window well connections to drain!

Foundation Drains

One Drain DischargeTwo Drain Discharges

Slope of Lot(Down)

Plan View Plan View

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CERTI©

Using Exterior Perimeter Drains (b)

Weeping Discharge (Soakaway) If water drains by gravity off

hillside open end must be modified to reduce air flow into system.

U-TrapLocate below frostline

Full size

Flapper (Backwater valve)Preferred

CERTI©

Using Exterior Perimeter Drains (c)

Fan Sizing Diagnostics before installation

Can connect vacuum cleaner to soakaway

Drill pilot holes to determine effective area

These are highly successful systems

Similar air flow from DTD as from a sub slab system if slab is reasonably sealed.

Watch for downspout and window well drain connections to exterior drain.

Don’t connect fan directly to soakaway - Connect to drain at house

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CERTI©

Using Exterior Perimeter Drains (d)

Fan Location HC Guidance allows fan to be below

grade

This is not allowed in U.S.

This can decrease freezing of moisture in fan housing and piping

Tips: Put in housing made for direct burial

Insure bottom drains

Insulated cover

Use electrical fan performance indicator


CERTI©

ASD Fan and Piping Installation Due to cold climate challenges - HC Guidance

allows for different fan and discharge locations

Item Canada U.S.

Fan location Inside building envelope Outside of building envelope

ASD discharge 30 cm or more above grade Above Roof

Fan below grade Allowed Not allowed

Piping runs and fan in cold spaces below 80 C

Insulate to reduce condensate Recommended in cold spaces

Exterior fan location Not recommended in cold climates even if insulated

Not required

• Condensation occurs at temperatures below +80 C• Freezing occurs at 00 C

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CERTI©

ASD Fan Speed Controller

HC Guidance suggests use of variable speed fan controller for ASD Fan

Adjust fan speed as a function of stack effect Lower speed in summer than winter

Install with continuous monitor that displays short-term radon averages to allow for adjustment.

CERTI©

System Routing

Fans can be indoors

Fans to be vertical

Fan can be in attic Consistent with U.S.

Insulate fan and piping in attic to reduce condensation

Photo: Radon West Ltd.

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CERTI©

ASD Discharge Install like combustion appliance vent

Criteria Distance Distance

Above grade 30 cm 12 in

From any window (operable or not) 30 cm 12 in

Building corners (inside or outside) 30 cm 12 in

Under porch (occupied area) 30 cm below porch/deck 12 in

Above sidewalk, driveway on public property* 2.13 meters 7 feet

Passive mechanical vents 30 cm 12 in

Mechanical air supply intake 7.83 meters 6 feet

* A vent shall not terminate directly above a sidewalk or paved driveway that islocated between two single family dwellings and serves both dwellings.

CSA-B149.1 Natural Gas and Propane Installation Code

CERTI©

Discharge Protection

Install screen

No rain cap!

Slope discharge down to help drain out condensate

Photos Courtesy of : Radon West Ltd.

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CERTI©

Interior Routing

Interior routing allowed Consistent with U.S.

Fan and piping to be insulated if located or routed through cold spaces

No rain cap

Varmint guard

36 inches24

inches

Supports

J-Box

Insulate

No - Rain CapYes - Varmint Guard

CERTI©

Condensate By Pass If fan must be located outdoors

Insulate and protect

Example: Below grade perimeter drain connection

Install condensate bypassCollects water above fan and

bypasses to suction

Insulated condensate line

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CERTI©

Vent Pipe

Parameter Spec

Wall thickness • Schedule 40*• STD

Minimum pipe size • 75 mm (3 inch)

Installation Guidance • Plumbing Code• Do block access areas for maintenance

* Thinner wall pipe (Sch. 20) is allowed in areas where pipe is unlikely to be damaged

CERTI©

Avoid Condensate Accumulation No traps in pipe

Slope pipe back to collection point

NO!

Condensate should flow

back to suction point

YES!

Pipe Size Air Velocity10 L/s

Air Velocity25 L/s

Air Velocity50 L/s

75 mm 1/50 1/30 1/8

100 mm 1/100 1/50 1/30

Recommended Slopes (Gradients)

Example: 1/50 = 1 cm drop for every cm of horizontal runNote: Air and water going in opposite directions therefore gradient increases as air velocity increases

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CERTI©

Multiple Foundations If air flows are significantly different, install damper

Install damper on highest air flow side

Basement

Tee

First Floor

Stem Wall

Depressurization System

to Common Fan

Slab

Crawl

CVC c

Crawl

Slab

CERTI©

Electrical for ASD Fan

Disconnect or plug within eyesight of fan

Components to be CSA or UL listed

Exterior Fan Locations: Run in conduit

Connect to integral junction box on fan

Wiring should not be routed through radon vent pipe or HVAC ductwork

Follow local codes Permanent Wiring: Electrical Inspection

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CERTI©

Other Codes Building Code

Pull permits and arrange inspections as required

Fire Code Fire collars when routing pipe through occupancy

separations (fire walls)

Maintain proper separation from hot surfaces (flues)

Some codes may require special treatment of membranes

Locate ASD system discharge similarly to vents for combustion appliances

CERTI©

Combustion Appliance Backdraft Test

ASD systems can pull additional air from home - especially if gaps in slab or membrane are not fully treated

A backdraft test should be completed after installation

Canadian Standard CAN/CGSB-51.71-2005

If appliance backdrafts: Notify building owner

Do not activate ASD system until problem corrected

Continuously operating CO monitor is recommended as part of any radon mitigation system

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CERTI©

Ventilation Approaches

These approaches were covered in detail in the CERTI mitigation course.

A few additional details are provided in the HC Guidance

CERTI©

Crawlspace Depressurization

Allowed

Low discharge

Floor needs to be sealed

Can increase infiltration of outdoor air

Heating system must have capacity

Close crawl vents

Not recommended if there are combustion appliances in crawlspace


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CERTI©

Pressurization

Adding supply air to crawlspace Discouraged

Dilutes crawl space radon but pushes radon up into building

Can freeze pipes

Simply adding air to building Discouraged

High heating penalty

Can push humid indoor air into shell insulation – Mold

Commercial buildings - this is often part of controlled fresh air scheme

CERTI©

Heat Recovery Ventilators Works more effectively in tight homes.

Sizing is same as discussed in CERTI course

Canadian Parameters:

Parameter

Condensate • Condensate line via trapped drain

Common natural ventilation rate • 0.3 - .4 ACH (200 m3/hr)

Air Intake • Minimum 30 cm above ground (12 in.)

Separation between supply & exhaust • Minimum 1.8 meters between grills

Discharge Grills • Co-axial intake/discharge vents not recommended• Double walled pipes with supply and exhaust in same run & discharge

Terminations • Vermin screen on supply and exhaust

Air flows • Balanced

Maintenance • Annual cleaning

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CERTI©

Sealing Entry Routs Example in HC Guidance

Illustrates that an opening in the foundation of 1 cm2 can account for the entry of radon needed to create 200 Bq/M3 in the home.

Floor to wall joints, gaps around plumbing penetrations and floor cracks each can present 100 cm2 of opening not to mention openings to soil from sumps.

Failure to seal more than 99% of any single one of these openings will result in failure.

Caulking and Sealing is not a stand alone technique - even in Canada!

CERTI©

Caulking and Sealing

Covered in base CERTI course

Polyurethane

Floor to wall joints: 2 cm. width of caulk

Caulk all accessible joints

Grinding and caulking floor cracks not feasible

Sealing openings nearest the suction point has the greatest benefit.

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CERTI©

Health and Safety Plan

Employer should have Health and Safety Plan for workers Review with employees annually

Acknowledgement by employee

Elements (not a full list) General site safety

Safe use of tools and equipment

Use of personal protective equipment

Confined space (crawlspaces)

CERTI©

Hazards (a) Asbestos(Not a complete List)

Insulation on hot water pipes and ductwork

Vermiculite can also contain asbestos

If friable asbestos is suspected, do not start work until accredited person determines you can proceed in accordance with asbestos regulations. Friable = crushable by hand

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CERTI©

Respirators

Higher efficiency respirators require fitness testing and medical surveillance

N95 does not require respirator program

N95 styleNegative Air PurifyingRequires Respirator Program

Protecting Your Home From Radon A Step by Step Manual for Radon Reduction

CERTI©

Hazards (b) (Not a complete List)

Crawlspaces/Attics Confined space

Broken glass, nails, discarded chemicals and drugs

Rodenticides

If large amount of rodent droppings hantavirus concerns exist (see later)

Spiders, snakes, critters

Additional ventilation for workers

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CERTI©

Hazards (c) Mold(Not a complete List)

Found in damp spaces like crawlspaces

Avoid contact

Wear protective equipment Disposable clothing

Gloves

N95 respirators

Wash hands and other contacted areas with soap and water after removing gloves.

If large amounts of mold have specialist team remove prior to initiating work.

CERTI©

Hazards (c) Histoplasmosis(Not a complete List)

Fungus from bird droppings, chickens and bats

Infectious droppings from some mammals

Avoid contact and inhalation Disposable clothing wash hands and other contacted

surfaces with soap and water

N95 respirator

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CERTI©

Hazards (d) Blastomycosis(Not a complete List)

Fungus in some soils containing rotting organic material

Avoid contact and inhalation Disposable clothing wash hands and other contacted

surfaces with soap and water

N95 respirator

CERTI©

Hazards (e) Hantavirus(Not a complete List)

Serious, fatal disease with flu like symptoms

Droppings and urine, feces and saliva from infected mice Can be found in attics and crawlspaces

If dead mice or droppings are observed Spray area with bleach solution (1 part bleach to 10 parts water)

Place suspected material in plastic bags for disposal

Wear disposable clothing, gloves, N95 respirator and goggles

Thoroughly wash with soap and water.

Engage specialist if large amounts of droppings observed.

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CERTI©

Radiation Exposure

This topic was covered in the Canadian Supplement for CERTI’s Measurement Course.

If you are not familiar with this topic and calculations involved, please review that program.

CERTI©

Post-Mitigation Testing

This topic was covered in the Canadian Supplement for CERTI’s Measurement Course.

If you are not familiar with this topic and calculations involved, please review that program.

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CERTI©

Elements of ASTM E2121-12Standard Practice for Installing Radon Mitigation Systems in

Existing Low-Rise Residential Buildings

Full document can be purchased at: http://www.astm.org/Standards/E2121.htm

CERTI©

ASTM E2121-12 Technical Details:

Some are in conflict with Health Canada Guidance Where conflict HC Guidance and local codes govern

Can provide additional details not covered by HC Guidance

Worker Health: Follow HC Guidance and Canadian Centre for Occupational

Health and Safety Rules

Practices: Suggested practices for record keeping and dealing with clients

Recognized by National Radon Proficiency Program

30



CERTI©

ASTM E2121-12 General Practices (a)

Prior to Starting Work Inform Client of:

Nature of work

Anticipated use of hazardous solvents or materials

Need to ventilate work area

MSDS sheets made available to client

Conduct visual inspection of property

Back drafting If a potential concern contractor should recommend

repairs to bring it into compliance

CERTI©

ASTM E2121-12 General Practices (b)

Installation Comply with Codes

Electrical Components: UL or CSA listed

Existing Systems Component replacement

Replacement to be in compliance with ASTM E2121

Non altered or repaired components not in complianceNot a requirement to upgrade untouched portions of system

Report non compliance to client in writing

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CERTI©

ASTM E2121-12 General Practices (c)

Design Design as permanent and integral system

Avoid creation of other health / safety hazardsBackdrafting

Obstruction of exits, normal pathways, maintenance access

Degradation of fire safety, e.g. passage through fire walls

Disturbance of asbestos

Other concerns:Energy costs, aesthetics, noise, durability, installation cost

CERTI©

ASTM E2121-12 - Labels System Description Label

Legible from 1 meter (3 ft.)

“Radon Reduction System”

Periodic Testing Advisory

Installer name and contact information

Pipe labels On each floor pipe is visible

“Radon Reduction System”

Power Panel Label circuit system is powered from

Membrane

Sump

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CERTI©

ASTM E2121-12 Client Documentation

Information to be provided to client after installation: Copies of contracts and warranties

Description of system including operating principals

Operating procedures Mechanical and electrical components

Manufacturer’s warranties

Interpretation of performance indicator including suggested actions to be taken

Contact information of installer Name, address and phone number

CERTI©

ASTM E2121-12 - Records

Records of Retention Duration

Records of all mitigation work done • 3 years , or• Duration of warranty if longer than 3 years

Health and Safety Records • including radon exposure logs

• 20 years

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CERTI©

Elements of ASTM 1465Standard Practice for Radon Control Options for the Design and

Construction of New Low-Rise Residential Buildings

Requires testing prior to occupation Active fan added if results > 4.0

or buyers expectation

Provides details on: Active fan routing

Allows for routing through garages and cold spaces

Soil collector options

Full document can be purchased at: http://www.astm.org/Standards/E1465.htm

CERTI©

Basic Concept and TermsBasic Concept and Terms

Cold jointor Caulk

Soil Gas Collector

Soil gas retarder

Ground Cover

Radon System piping thru roof

Gas permeable layer

Sealed penetrations

Slab Crawlspace

Radon System piping thru roof

Ground Cover

Soil gas retarder

Soil gas collector

Sealed

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CERTI©

Treat All Areas within FootprintTreat All Areas within Footprint

Basement slabs

Slab-on-grade

Crawlspaces

Garages*

Enclosed patios

Utility rooms

Wine cellars

Enclosed entry ways

Storage vaults

* Per ASTM 1465 - Appendix F of IRC does not require treatment of garage

ASTM 1465 Logical Interpretation

CERTI©

Ground CoverGround Cover

Caps the top of the gas permeable layer Concrete FloorsConcrete floor serves as “cap” or Cover

Earthen areas – CrawlspacesMembrane –

Sealed seams, sealed penetrations, sealed edges to wallsMinimum: 6 mil poly or 3 mil high density

Concrete If storage or light traffic planned: 2 inch rat slab If equipment in crawlspace: Full 3 ½ inch slab

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CERTI©

Areas of High Permeability in Underlying Soil –Seal Bottom of Gas Permeable Layer

Areas of High Permeability in Underlying Soil –Seal Bottom of Gas Permeable Layer

Porous Native SoilsKarst

Decomposed granite

Blasting

Plastic under gas permeable layer Blocks air from

belowMembrane under gas permeable layer

GPL Cover

• Slab or

• Membrane in crawlspace

Membrane under gas permeable layer not needed in cases where native soils are impermeable

CERTI©

Maintaining Lateral Flow in Gas Permeable Layer

Maintaining Lateral Flow in Gas Permeable Layer

Horizontal runs of utility pipes and conduits (water, sewer, electric, phone, TV and so forth) and other barriers that restrict air flow to any part of the gas permeable membrane shall be avoided. (Section 6.4.1 ASTM 1465)

Exception:If interior perimeter drain is used as the soil gas collector

See next slide

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CERTI©

Sub-Slab Utility LinesSub-Slab Utility Lines

Minimum 4 -inch

Soil gas collectorSeal

Minimum 4 -inch

Soil gas collectorSeal

*Per ASTM 1465, allowed in App F of the IRC

Soil gas retarder

Soil gas retarder

Maintain full 4-inch area for soil gas movement

OK

Not OK *

CERTI©

Alternative to Trenching Utility Lines*Alternative to Trenching Utility Lines*

If utility line does not completely cut-off portion of sub-grade

Maintain minimum of 2 feet of clearance around utility line

* Personal recommendation of D. L. Kladder

Soil Gas Collector

Plan View

Sewer or utility lines

NOSection Isolated

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CERTI©

Soil Gas RetarderSoil Gas Retarder

Slab: Plastic sheet between bottom of concrete and Gas

permeable Layer Keeps concrete from entering GPL Helps bridge future slab cracks

Crawlspace Plastic sheet on top of soil, with Soil gas Collector &

Membrane above it Protects membrane

Sealing No sealing required – seal provided by Ground Cover Seams overlapped 12 inches Installed as required for moisture barrier.

Soil Gas Retarder

Soil Gas Retarder

CERTI©

Gas Permeable Layer (GPL) - SlabsGas Permeable Layer (GPL) - Slabs

Specification depends upon soil gas collector design

Four types

Common aspects:100% coverage of footprint

Aggregate with low fines when used

Located under Soil Gas Retarder

38



CERTI©

Slabs – Type I Gas Permeable Layer Larger Rock – Less Perforated Pipe

Slabs – Type I Gas Permeable Layer Larger Rock – Less Perforated Pipe

Slab

Soil gas retarder

4 inch layer washed stone#4 (1 to 1½ inch)

4-inch diameter soil gas collector

•4-inch diameter soil gas collector

•Minimum 20 feet long

•Open endsRadon Riser

Radon riser

CERTI©

Type I LayoutType I Layout

© CVC

Conform to footprint At least 24 inches from interior footing drains* RiserDirectly on pipe, orOffset to wall with non-perforated 4-inch

* D.L. Kladder recommendation-assumes interior drain not used as soil gas collector

39



CERTI©

Type I Allowing for Lateral Air Flow

Post and Beam Foundation with Grade Beam

Do not draw air from one perforated pipe through another to a riser

Riser

CERTI©

Slabs – Type II Gas Permeable Layer Moderate Sized Rock - Loop of Perforated Pipe

Slabs – Type II Gas Permeable Layer Moderate Sized Rock - Loop of Perforated Pipe

Soil gas retarder

4 inch layer washed stone#6 (1/2 – 3/4 inch)


Slab


•Loop of perforated pipeRadon Riser

Radon Riser

40



CERTI©

Type II LayoutType II Layout

© CVC

Conform to footprint

At least 24 inches from interior footing drains*

RiserDirectly on pipe, or

Offset to wall with non-perforated* D.L. Kladder recommendation-assumes interior drain not used as soil gas collector

CERTI©

Slabs – Type III Gas Permeable Layer Rock in Trench – Loop of Pipe

Slabs – Type III Gas Permeable Layer Rock in Trench – Loop of Pipe

Slab

Soil Gas Retarder

Trench 1 foot wide x 4 inch deep layer washed stone

#4 (1 to 1½ inch)



•Loop of perforated pipe

•Laid in trenchRadon Riser

Radon Riser

41



CERTI©

Perforated Pipe Option: Cross-Overs

Make provisions for pipe to penetrate obstructions.Short lengths laid in

trenchesTape ends to keep clear of

debris - attach to main loop after grade beam finished

Pipe sleeves in intermediate footings.Pass perforated pipe through.

Garage Grade Beam

Pipe Loop

Riser

Important: when passing under grade beams make sure that

perforations of pipe allow drainage

CERTI©

Perforated Pipe Option: Riser

Corrugated, PerforatedPolyethylene pipe 8” stub of 4” PVC Pipe

Slab

Sch. 40 PVC or ABS Pipe

PVC or ABS Pipe Coupling or flexible boot in expansive soils

Tee and Perforated Pipe Same Diameter as Vent pipe.

42



CERTI©

Slabs – Type IV Gas Permeable Layer Drain Mat No Aggregate Other than Normal

Slabs – Type IV Gas Permeable Layer Drain Mat No Aggregate Other than Normal

Slab

Soil gas retarder

Radon Riser

•12 in. x 1 in. drain mat•Rectilinear loop

Radon Riser

CERTI©

More expensive Offset by: Easier

installationNo special

aggregateLaid on subgrade, with vapor retarder between

it and bottom of slab

Drain Mat (Proprietary Mat)

© CVC

43



CERTI©

Mat Option: Layout

Garage Grade Beam

Mat

Riser

Tee and mat to have same cross-sectional free flow area as vent pipe.

2000 4000

6000

CERTI©

Installation of MatInstallation of Mat

Roll out Mat Make corners Place under re-bar

Install Riser Pour concrete on top of mat

Finish Slab

Photos: Compliments of Professional Discount Supply

44



CERTI©

Cross-OversCross-Overs

Plan for mat to cross through barriersThrough intermediate foundation

walls

Under grade beams

Insure that concrete does not enter mat and that water can drain into sub-grade!

Mat laid over footing prior to pouring of post-tension slab.

Mat being routed under intermediate foundation wall and to another slab level

CERTI©

CrawlspacesCrawlspaces

45



CERTI©

Ground Cover for CrawlspacesEarthen Areas – Case A - No Traffic or Storage

Ground Cover for CrawlspacesEarthen Areas – Case A - No Traffic or Storage

No traffic or storage Sealed Ground Cover

membrane 6 mil normal 3 mil high density

Vapor barrier beneath membrane*

Additional sheet over ground cover membrane for occasional traffic area.

* ASTM 6.1.3.3

Radon System Piping thru roof

Ground Cover

Soil gas retarder

Soil Gas collector

Sealed

CERTI©

Soil Gas Collector – Crawlspace*Soil Gas Collector – Crawlspace*

If no aggregate addedLoop

If 4-inch layer of aggregate added20 foot length allowed

*ASTM 1465, not stipulated in App. F of IRC

4-inch layer of aggregate below membrane

No aggregate added under membrane

46



CERTI©

Ground Cover for Crawlspaces Earthen Areas Case B & C - Planned Traffic & Storage

Ground Cover for Crawlspaces Earthen Areas Case B & C - Planned Traffic & Storage

Radon System Piping thru roof Planned traffic & Storage

Poured slabEquipment in crawl

water heaters, furnace, etc

3 ½ inch slab

Storage and traffic expected2 inch rat slab

Soil gas retarder

Soil Gas Collector

Poured slab

Use Type I, III, III or IV for slab design

6.1.3.1 and 6.1.3.2

CERTI©

Places to Seal at SumpsPlaces to Seal at Sumps

Soil retarder to base of sump before slab pour

Seal Lid Penetrations• Discharge pipe• Electrical cord

Gasket on Lid Bolt Down Lid

Caulk Base

Label Lid – Advising:

• Part of radon system

• Replace if removed

• Turn off fan if active system

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CERTI©

Radon Vent Pipe SystemRadon Vent Pipe System

Connected after sub-grade system installed

Pipe cannot be trappedProvide space in chases

Support at each floor level Discharge through roof behind ridge

© CVC

CERTI©

Post Construction Testing and System Disclosure

The proposed methods are prescriptive - not performance based.

Testing is better performed after occupation.

The need for further reductions is decision by occupant.

Disclosure should be made to occupant (and future occupant) of systems existence and need to test to verify efficacy.

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CERTI©

Documentation to Buyer ??Documentation to Buyer ??

Passive:Need to test

Do not assume radon levels are acceptable

Who activates?

ActiveMonitor / Indicator & retest

Fan to run continuously

Elements that impact performanceSump lid

Crawlspace membrane

CERTI©

Active System Operation and MaintenanceActive System Operation and Maintenance

Fan in atticRuns continuously (60 watt)No lubrication or maintenance requiredLife: 10-15 yearsReplacement cost: $150

Performance IndicatorShows vacuum in systemNot a radon monitor

Membrane tape for large tears in crawlspace barrier

Monitor Confirms Vacuum

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CERTI©

Additional Resources and UpdatesAdditional Resources and Updates

Center for Environmental Research and Technology, Inc.

© 2013

Organization URL

Health Canada http://hc-sc.gc.ca/index-eng.php

Center for Environmental Research and Technology, Inc. www.certi.us

Canadian National Radon Proficiency Program http://nrpp.info/cnrpp.shtml

If you are viewing this program as part of a CERTI course be sure to check out the resource section for

additional tools and resources

canadian supplement to certi radon mitigation...

Documents