Wet Basement Repairs

What is a Crawl Space?

A crawl space (as the name suggests) is a type of basement in which one cannot stand up — the height may be as little as one foot, and the surface is often soil. They offer a convenient access to pipes, substructures and a variety of other areas that may be difficult or expensive to access otherwise. While a crawlspace cannot be used as living space, it can be used as storage, often for infrequently used items. Care must be taken in doing so, however, as water from the damp ground, water vapor (entering from crawlspace vents), and moisture seeping through porous concrete can create a perfect environment for mould/mildew to form on any surface in the crawlspace, especially cardboard boxes, wood floors and surfaces, drywall and some types of insulation.

Health and safety issues must be considered when installing a crawl space. As air warms in a home, it rises and leaves through the upper regions of the house, much in the same way that air moves through a chimney. This phenomenon, called the “stack effect,” causes the home to suck air up from the crawlspace into the main area of the home. Mould spores, decomposition odors, and fecal material from dust mites in the crawlspace can come up with the air, aggravating breathing problems (such as asthma) and creating a variety of health-related problems.[4]

It is usually desirable to finish a crawlspace with a plastic vapour barrier that will not support mould growth or allow humidity from the earth into the crawlspace. This helps insulate the crawlspace and discourages the habitation of insects and vermin by breaking the ecological chain in which insects feed off the mould and vermin feed on the insects, as well as creating a physical inorganic barrier that deters entrance into the space. Vapour barriers can end at the wall or be run up the wall and fastened to provide even more protection against moisture infiltration. Some pest control agencies recommend against covering the walls as it complicates their job of inspection and spraying. Almost unheard of as late as the 1990s, vapour barriers are becoming increasingly popular in recent years, in fact, the more general topic of conditioned vs. unconditioned crawlspaces has enjoyed much research over the last decade.

It is usually desirable to finish a crawlspace with a plastic vapour barrier that will not support mould growth or allow humidity from the earth into the crawlspace. This helps insulate the crawlspace and discourages the habitation of insects and vermin by breaking the ecological chain in which insects feed off the mould and vermin feed on the insects, as well as creating a physical inorganic barrier that deters entrance into the space.

Vapour barriers can end at the wall or be run up the wall and fastened to provide even more protection against moisture infiltration. Some pest control agencies recommend against covering the walls as it complicates their job of inspection and spraying. Almost unheard of as late as the 1990s, vapour barriers are becoming increasingly popular in recent years, in fact, the more general topic of conditioned vs. unconditioned crawlspaces has enjoyed much research over the last decade.

Crawl space is traditionally the most misunderstood part of your home. It encompasses many crucial building components of the foundation.

A compromised crawl space endangers the structural integrity of the foundation system.

Damage occurs when the environment is moist, exposing joists, sill plate, support beams, subfloor, piers, block foundation walls, etcetera, to undesirable temperatures and water vapor levels.

Crawl Spaces Key Considerations

• The age of your home and the type of construction are important factors as well as and if wooden frame or metal frame has been used in construction. As your home is relatively new – does it have built-in insulation within the foundation walls.
• The condition and R-value of the present insulation and if it would be more cost effective to leave it in place and add more to increase the insulation without over insulating and compressing the material.
• It is very important to know if the crawl space is ventilated or not – traditionally building codes required the installation of vents during home construction but in many areas this is now no longer the case and vents are being blocked.
• There are two ways to find out – your local building office will be able to advise you – and a qualified insulation contractor will know the building code requirements for your home type in your area.
• Unventilated crawl spaces allow for insulation of the crawl space walls as an option to insulation suspended below above floor structure – but only if the space is dry throughout the year AND the floor above is not insulated.
• Do you have a durable vapor retarder like a thick polyethylene film properly installed on the ground area over all of your crawl space – this is a very important factor in reducing the amount of moisture that gets into the space.
• Spray foam insulation may also ‘by code’ require the additional installation of an air barrier.
• Get that valuable certificate proving insulation work done on your home.

Quality builders and concerned homeowners use reputable companies such as Basement Solutions Vancouver on all their projects to ensure their homes have dry basements and crawl spaces!