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| Home Moisture Audit |
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by Jim LaRue, HouseMender Inc. for Environmental Health Watch Home Moisture Audit Overview
1. Where did the moisture come from – the source. 2. How did the moisture get to where it caused the problem – the path. 3. Was the moisture a vapor, in bulk or a condensate or combination of the three – the moisture form. 4. Was it gravity, air pressure, capillarity, or diffusion that carried the moisture from one place to another – the driving/pulling force.
1. A site specific moisture problem where the problem, source, and path are all close together: the location of the problem, the source of the moisture, and the path of the moisture are all close together and easily identifiable. For example, water leaking into the corner of a basement (form:bulk) is likely coming in through openings in the basement wall (path), the water is coming from the downspout that is spilling water in this corner of the house (source) and gravity is carrying the water in (driving/pulling force). Some can be surface water and some from a broken storm drain, but it is all associated in the same area. 2. A moisture problem where both the moisture source and path are not obvious at all and significant investigation is required to try and find them. For example, a cathedral ceiling roof, with many recessed lighting fixtures (path) creating holes between the inside of the house and the roof surface, is rotting because of all the moisture (vapor) these little "chimneys" have sucked out of the apparently dry basement walls (source) is condensing on the underside of the roof sheathing during the cold winter months. If you have a moisture problem, where do you start? A word of caution: never jump to immediate conclusions about what the solution to your problem may be. Finding a successful solution to one moisture problem does not mean it will always work for every other problem that appears to be like it. Deal with each problem on its own terms. Step One: Using Moisture Audit Worksheet #1 define the problem as specifically as possible. Some examples: § paint is peeling on the clapboard siding on the south side of the house § some framing attached to the basement walls is covered with mold near the bottom § the plaster under a window is falling off the wall § mold is growing on the interior of an outside wall where it meets the ceiling § the crawlspace in the basement has had six inches of water standing in it for a week § a resident is having severe asthma attacks when in the house § a resident is complaining of burning in the nose when in the house Step Two: Using the worksheet(s) that are most applicable for your problem. Note all those factors which you think are relevant to finding the source and path of your moisture. It may be necessary to use more than one. § Moisture Audit Worksheet #2: Exterior Walls (inside and out) § Moisture Audit Worksheet #3: Foundation Walls (inside and out) § Moisture Audit Worksheet #4: Roof Surfaces (inside and out) § Moisture Audit Worksheet #5: Mechanical Systems (plumbing, HVAC) § Moisture Audit Worksheet #6: Interior Framing and Surfaces Step Three: If the issue that is driving this audit is a health problem of one of the residents then you should use Moisture Audit Worksheet #7 to guide your search for the moisture, mold and/or any other offensive material or organism. § Moisture Audit Worksheet # 7: Moisture Related Health Issues Moisture Audit Worksheet #1: Defining The ProblemDescribe the moisture problem as specifically as you can: Given what you have described, try to answer as many of the following questions as possible: § Is the problem related to the seasons of the year? § Is the problem only evident when it rains or snow melts? § Is the problem related to any activity by a resident? § How many persons have been living in this residence during the course of this problem? How many before this problem? § What repairs, replacements or additions were made to the house in the weeks/months prior to the problem’s appearance?
Specifying the Problem: 1. Condition That May Be Caused By Moisture On Exterior Walls (exterior) _____ peeling paint _____ deteriorated siding _____ rotted window sills _____ rotted window/door trim _____ brick/stone/mortar damage _____ rotted sheathing _____ rotted framing members, including sill plates _____ other:
(interior) _____ plaster damage _____ paint peeling _____ wallpaper peeling _____ mold on and/or behind wallpaper _____ mold on walls _____ rotted sheathing _____ other:
Diagnosing The Problem: 1. Orientation of wall: (circle one): N, NE, NW, S, SE, SW, E, W. 2. Wall Details: _____ platform construction/ _____ balloon construction/ _____brick veneer/ _____other Wall composition: exterior surface is ___ sheathing is ___ interior surface is ___ insulation in the wall ______ made of ___ _____ there are heat _____ ducts/ _____ pipes in wall _____ there are _____ water service and/or _____ waste lines in wall _____ siding is closer than 6" to the ground _____ closets on exterior walls Window type(s) and number of each in this wall: _____ double hung _____ casement _____ fixed _____ slider _____ other _____ single pane _____ double-glazed _____ argon or other gas _____ low-e _____ wood _____ wood @ ext. cladding _____ vinyl _____ metal Manufacturer of window: _ Storm window type(s): _____ triple track aluminum _____ wood _____other 3. Possible Moisture Sources: _____ ice backup (heating climate) _____ blocked rain gutter spilling water into wall _____ wind driven rain _____ leaking heat pipes _____ leaking water/waste lines _____ blocked weep holes in storm windows _____ interior moisture level (relative humidity too high) _____ interior surface temperature below dewpoint temperature _____ leakage around windows/door 4. Possible Moisture Paths: _____ leaking through openings in walls and/or through floors _____ moisture vapor convected through wall openings _____ moisture extrusion through wall surfaces _____ moisture splashing up under siding _____ moisture via capillary action up behind siding _____ moisture via capillary action through masonry _____ condensate from humid inside air. 5. Exploratory "surgery" and testing to confirm diagnosis: _____ remove some plaster or drywall _____ remove some siding _____ spray water on side of house to see if windows/doors leak
Correcting The Problem: 1. Corrective measures: a. remove (repair) moisture source: b. divert moisture source: c. block moisture source: d. block moisture paths: e. ventilate the moisture source: f. control surface temperature/room temperature 2. Levels of moisture reduction to be achieved: a. all leaks bringing bulk moisture into the structure are corrected b. humidity controlled in the 40 % RH range on the interior 3. Older homes with too many layers of paint that most likely has lead in it may require installation of vinyl or aluminum siding. Moisture Audit Worksheet #3: Foundation Walls (inside and outside) Specifying The Problem: 1. Condition That May Be Caused By Moisture: (exterior) _____ holes through the wall: _____ below grade and/or _____ above grade _____ spalling mortar joints _____ deteriorating masonry surface _____ paint peeling _____ collapsing window well(s) _____ rotted window/door sills _____ other:
(interior) _____ holes through the wall: _____ below grade and/or _____ above grade _____ horizontal and/or vertical stress cracks in foundation wall _____ spalling mortar joints _____ efflorescence _____ spalling masonry surface and/or coating _____ deteriorated/moldy wood framing on masonry wall _____ deteriorated/moldy surface materials such as drywall, paneling, etc. _____ general wall damp _____ water flowing through wall into basement _____ other:
Diagnosing The Problem: 1. Orientation of Foundation Wall: (circle one): N, NE, NW, S, SE, SW, E, W 2. Nature of Interior Space: _____ full interior basement _____ crawlspace (conditioned ______/ unconditioned _____) _____ slab 3. Foundation Wall Details: Wall composition: _____ all brick _____ all concrete block _____ all poured concrete _____ all stone _____ combination brick and stone _____ combination brick and clay tile _____ combination brick and concrete block _____ other: Window type(s) and number of each in this wall: _____
double hung _____ awning ____ hopper
_____ glass block 4. Grade Details: _____ grade level is _____ inches below the bottom edge of the siding _____ basement window sills are __________ inches above the grade _____ basement windows are surrounded with window wells of ______ masonry/ ______ metal _____ there are flower beds along this wall _____ there is shrubbery along this wall: type _________________; size _________________ _____ there is a tree(s) close to this wall: type _________________; size _________________ _____ there is a _____ concrete/ ______ asphalt/ ______ gravel driveway along this wall _____ there is a _____ concrete/ ______ asphalt/ ______ gravel driveway along this wall _____ the driveway is _____ right up against the house/ _____ inches from the foundation wall _____ the driveway pitches toward the house _____ the patio pitches toward house _____ the sidewalk pitches toward the house _____ there is a side door through this wall and the threshold is ______ inches above the grade level _____ there are storm drain crocks for downspouts along this wall _______ (number) _____ storm drains _____ run to daylight/ _____ are connected to a city storm system _____ sewer system is _____ septic/ _____ connected to city sewer _____ there are _____ yard drains/ _____ driveway drains _____ there ______ are/ _____ are not splashblocks under the downspouts 5. Crawlspace, Basement, Slab Floor Condition a. crawlspace: _____ dirt only _____ concrete only – condition: _____ cracks/ _____ holes/ _____ spalling _____ combination – concrete condition: _____ cracks/ _____ holes/ _____ spalling b. basement floor: _____ dirt only _____ concrete only – condition: _____ cracks/ _____ holes/ _____ spalling _____ combination – concrete condition: _____ cracks/ _____ holes/ _____ spalling c. slab: _____ slab condition: _____ cracks/ _____ holes/ _____ spalling 6. Possible moisture sources: _____ storm water spillage from gutters _____ clogged or broken storm drains _____ backed up city storm and/or sewer system _____ wind driven rain _____ storm water grading toward house _____ water table rising _____ unvented clothes dryer/hanging clothes in basement _____ unvented basement bath/shower 7. Possible moisture paths: _____ leaks through wood framing that ends up in the basement _____ leaks around window and door framing (especially under thresholds) _____ leaking through holes/cracks in foundation walls _____ moisture wicking through mortar joints and masonry materials _____ moisture carried in heating ductwork under a slab _____ moisture vapor from bathing, clothes, or clothes being dried in the basement _____ moisture vapor from soils in a crawlspace or from open top concrete block walls 8. Exploratory "surgery" and testing to confirm diagnosis: _____ temporarily remove downspouts from storm drains and run water away from house on ground _____ have each storm drain crock snaked to check blockage; snake main line to city storm in street _____ storm drains surveyed with a camera to locate leaks and condition of storm drains _____ if practical, fasten plastic sheeting to siding, down to the ground and out 3' on ground for just a few rainstorms to see if surface water could be the problem _____ fill obvious holes in foundation walls with appropriate materials _____ tape all four sides of a one foot square piece of plastic to wall and or concrete floors to see if moisture is wicking through these surfaces or if condensate forms on outer surface of the plastic
Correcting The Problem: 1. Corrective Measures: a. remove moisture source: _____ Mother Nature is not likely to be cooperative b. divert moisture source: _____ secure and properly pitch gutters and downspouts; when possible and code permits, disconnect downspouts from storm systems and run water on ground away from structure or redesign gutter system so less of the underground storm system will be required _____ avoid flower beds around the perimeter of the house _____ grade soils away from the house _____ "flash" soil to house with EPDM roofing materials _____ install full exterior excavation and drainage system _____ install interior moisture control measures including sump pumps c. block moisture source: _____ fill holes/cracks in masonry surfaces _____ apply dampproofing materials on exterior _____ avoid cementitious waterproofing coatings on interior (efflorescence can cause them to spall) _____ close up subslab heating/cooling ductwork; replace heating system _____ install polyethyelene plastic on the surface of a dirt floor crawlspace d. ventilate the moisture source: _____ use a dehumidifier to reduce relative humidity in space _____ vent clothes dryers directly to exterior _____ vent basement baths (showers) directly to exterior e. control surface temperature/room temperature with heating or insulation _____ can keep condensate from forming on foundation walls giving appearance of an exterior moisture problem. f. remove or protect any cellulose material from foundation walls/floors. _____ use plastic shelving away from the walls to store things; when remodeling a basement, use moisture impermeable materials on walls before framing and finish materials are installed 2. Levels of moisture reduction to be achieved: a. all leaks bringing bulk moisture into the structure are corrected b. humidity controlled in the 40% RH range on the interior 3. Other preventive measures required to reduce possibility of moisture problems: a. protect interior building materials used along foundation walls from possible moisture damage b. store materials in a basement on plastic or vinyl-covered steel shelving Moisture Audit Worksheet #4: RoofSpecifying The Problem: 1. Condition That May Be Caused By Moisture: _____ roof sheathing wet, rotting, moldy _____ roof rafters wet, rotting, moldy
Diagnosing The Problem: 1. Roof Details: _____ roof surface: _____ asphalt/fiberglass/ _____ wood shakes/ _____ slate _____ how many layers of roofing material _____ type of sheathing: _____ 1 x 6/ _____ plywood/ _____ OSB _____ ice guard installed along roof edges: tucked behind gutters: _____ yes/ _____ no _____ drip edge installed on ______ eave edge and/or _____ rake edge _____ soffit venting: _____ hole vents/ _____intermittent vents/ _____ continuous vent _____ roof venting: _____ ridge vent/ _____ roof vent/ _____ gable vent/ _____ powered vent _____ other roof penetrations: _____ chimney(s)/ _____ plumbing stack(s)/ _____ bath fan vents 2. Possible Moisture Sources: _____ ice backup along eaves _____ wind driven rain/snow blowing in _____ rain leaking in _____ moisture vapor from interior (see mechanical and interior framing worksheets) _____ moisture vapor from exterior 3. Possible Moisture Paths/Conditions: _____ ice backup leaking in along eave edge _____ wind driven rain/snow via roof vents _____ water leaking in through holes in roof _____ water leaking in around flashings _____ vapor via thermal by-passes in attic floor (recessed lights, bath fans, mechanical openings, framing openings) _____ dewpoint temperature achieved in attic _____ exterior moisture vapor entering via roof vent openings 4. Exploratory "surgery" and testing to confirm diagnosis: _____ seal thermal bypasses into attic; replace or remove recessed light fixtures _____ remove section of plaster where water leaked to better assess source
Correcting The Problem: 1. Corrective Measures: a. remove (repair) moisture source: _____ Mother Nature is not likely to be cooperative b. divert moisture source: _____ repair all roof surface leaks _____ replace all roof surfaces c. block moisture source: _____ install ice guard on eave edge of roof _____ caulk joint between roof sheathing and fascia board _____ repair flashings d. ventilate the moisture source: _____ does thermal by-pass treatment reduce need for ventilation _____ do existing vents create a problem, not solve one e. control surface temperature/room temperature: _____ does keeping attic cooler reduce ice backup 2. Levels of Moisture Reduction To Be Achieved a. all leaks bringing bulk moisture into the structure are corrected b. paths for vapor moisture to enter the attic from the interior are blocked, controlling RH level 3. Other preventive measures required to reduce possibility of moisture problem:
Mechanical Systems As Contributors To Moisture Problems: 1. Plumbing: _____ Leaks: _____ water service lines: _____frozen pipes _____corrosion _____ waste stacks and lines: _____frozen pipes _____corrosion
_____ overflowing caused by: CARELESSNESS BROKEN FIXTURES/CONNECTION _____ tubs _____ sinks _____ toilets _____ water heaters _____ clothes washers _____ garbage disposals _____ dishwashers _____ Sewer/Storm Water System Failure: _____ backup of clogged and/or broken sewer/storm water lines around house and to street _____ sump pump fails
_____ Hot Water/Steam: _____ leaking radiators _____ leaking/corroded pipes _____ Forced Air Heating: _____ heat ducts under a slab with water leaking into them can act as a humidifier driving moisture vapor into the house _____ heat ducts traveling through a crawlspace can pick up mold spores _____ open cold air returns into basement can carry mold spores and moisture from basement to living spaces _____ heat ducts in exterior walls can pick up mold spores _____ Air/Conditioning: _____ units are oversized and do not dehumidify effectively _____ units are oversized and space gets too cold and condensation forms _____ Venting: _____ no bath fans to remove shower moisture _____ no kitchen fan to remove cooking moisture _____ powerful exhaust fan (such as Jenn-Aire) backdrafts furnace, hot water tank _____ fans in place are not used regularly _____ Metal or PVC Flues: condensate forms from flue gases and water drains back down the flues _____ Chimneys: _____ flues are too large for gases of higher efficiency furnaces/boilers and moisture condenses in the chimneys and wicks into the walls of the chimney, causing spalling of the chimney face and/or surfaces applied to the chimney _____ flues get clogged up with leaves and other debris and blocks the openings in them so that CO gases and moisture cannot escape _____ Unvented Gas Heaters: can off gas CO and generate large amounts of moisture when gas burns
_____ Thermostat settings: too low a setting can cause dewpoint temperatures to be reached on walls and windows with resultant condensate forming Strategies To Help Make Mechanical Systems Work For You, Not Against You
_____ keep all water and waste lines inside the conditioned space, so they cannot freeze _____ carefully and fully insulate any water/waste line that must pass through unconditioned spaces _____ address leaking plumbing fixtures immediately, lest the moisture contribute to mold growth and/or destroy critical structural components of the structure _____ keep sewer and storm system lines snaked out; if residence is subject to city sewer and storm water backup, consider installing check valves on these lines to reduce this backup 2 Heating/Cooling/Air Conditioning/Venting: _____ address leaking pipes that may be carrying hot water or steam for heating _____ seal off a failed sub-slab ductwork forced air system and replace it with an above grade heating system _____ seal all accessible duct joints on a forced air system with a mastic to keep moisture and mold spores from entering the system or being carried somewhere else by the system _____ cold air returns for forced air systems must be connected directly to the furnace and the air should not travel through any area not regularly used for living space _____ when installing any new piping or ductwork, it should always be within the conditioned space and not in the walls or other unconditioned spaces _____ bath and kitchen ventilation fans must vent directly to the exterior _____ to encourage fan usage, connecting the fan to the light switch in the bathrooms means it will be on whenever someone has turned on the light to use the bathroom _____ use no unvented gas appliances (including natural gas, kerosene, etc) _____ keep wire screens on top of chimney flues to keep debris and critters out _____ whenever new heating equipment is installed be sure it is sized properly, is properly vented, and whenever possible, it is a unit that gets its combustion air from outside the residence and ventilates the flue gases directly to the exterior _____ whenever new air conditioning units are installed, be sure they are properly sized and that the condensate formed by these units is properly drained away _____ check chimney cleanouts and be sure chimney is not blocked in any way by debris
_____ bath fan venting directly into the attic (moisture can condense on the cold roof sheathing) _____ recessed light fixtures into the attic _____ mechanical system holes through this surface including: _____ around light fixtures _____ around plumbing stacks that eventually go through the roof _____ doors and hatch openings into the attic space
_____ opening between chimney(s) and wood framing around them _____ balloon construction framing open from the basement all the way to the attic _____ chases in which mechanical lines or ducts are run and may be open from the basement to the attic _____ soffits over kitchen cabinets and other places which may be open to side walls and floors on outside walls
The primary remedial measure with these moisture paths is to block or close them off so no moisture can move through them to where it can do damage. ______ around non-heat generating openings (such as recessed and other light fixtures and chimney collars) you are blocking or closing off in the attic, seal openings with plastic sheeting, caulk, foams ______ around heat generating openings follow specifications of light fixture manufacturers; around chimney collars create a metal flashing from coil stock that is secured to the chimney and framing with adhesive caulk ______ openings in framing in the basement can be blocked or closed off with styrofoam insulation cut to fit the openings and sealed around the perimeter with caulk or foams compatible with styrofoam
q Lead paint failure is often caused by moisture problems. It results in loose and flaking paint that contaminates household dust on the interior and soil on the exterior. q A number of allergic asthma triggers are associated with excess moisture, including house dust mites, mold and cockroaches. q Outgassing of some volatile chemicals found in building products, such as bonding agents, is increased by higher building relative humidity. q Mold growth from excessive moisture may have allergenic or toxic health affects.
Have medical tests identified things that the residents are allergic to? If so, are they allergens related to excess moisture? Do the residents with the health complaints experience discomfort only while in the residence? Is there a particular place in the residence where they are most uncomfortable? Can you connect the moisture problem identified with an exposure pathway? (For example, foundation wall water intrusion may result in toxic mold growth in the basement. A cold air return that opens into the basement and is not connected to the furnace can provide mold spore exposure pathway to an infant who’s crib is near the cold air return in an upper bedroom.) |