It is said that more than 98% of all houses have had, or will have, basement leakage at some point.
Identify the Problem:
The presence of efflorescence, a whitish mineral deposit on the interior of foundation walls, indicates moisture penetration. It should be noted that the severity of the problem, or whether the problem is active, is not indicated by the amount of efflorescence. Other clues are rusty nails in baseboards, rotted wood near floor level, rusted metal feet on appliances, mould and mildew, lifted floor tiles, storage on skids, peeling paint and the presence of dehumidifiers.
Corrective Action:
Poor surface drainage is one of the main causes of basement leaks. The ground should slope away from the house a rate of one inch per foot for at least the first six feet. As a preventative measure, seal where the driveway and sidewalk meet the foundation walls. The eavestroughing and downspout systems must also perform properly. If downspouts are ever suspected of being disconnected, broken or clogged below ground level, they should be redirected to discharge above grade at least six feet away from the house. Also, eavestroughs should be kept clear of debris.
Localized low areas including basement stairwells, window wells, et cetera, may allow water to collect. Drains should be provided in the bottom of these. Where there are no drains, plastic dome covers over the window wells allow light into the basement while minimizing water and snow accumulation.
More Extreme Measures:
In the vast majority of cases, basement leakage is not significant from a structural point of view and can be controlled relatively inexpensively, as discussed above. However, the presence of foundation cracks, damaged perimeter drainage tiles, a high water table or underground streams may call for more extreme corrective measures. These measures are used when chronic flooding occurs.
Sealing foundation cracks can be performed several ways with the cost of repairs varying. The approach taken depends on the specific crack. however, the most successful approach is sealing from the outside (Cost $500 - $800). Epoxy injection repairs can be done from the interior on poured concrete walls only (cost $400 - $600). Excavating, damp proofing and installing drainage tiles should be used as a last resort. Damp proofing on the exterior typically involves parging a masonry foundation wall with a one- quarter inch layer of mortar covered with a bituminous or plastic membrane which extends down to the footings, The drainage tile laid beside the footing is covered with gravel and filter paper. These tiles can often be damaged or clogged by roots and some localized repairs may be required.
Because excavating on the exterior is expensive ($8,000 - $15,000 typically), an alternative is an interior drainage system. The cost of this approach is one-third to one-quarter the cost of exterior work. There are many cases where this proves satisfactory, although this must be judged on a case-by-case basis.
Where underground streams and/or a high water table are present, sump pumps are usually required.
There's a great deal of misinformation out there about dry rot, the first bit being the name. It's technically called brown rot, but probably because it forms dry brown cubes, the term dry rot has stuck.
If we examine dry rot (called brown rot from here on) in a logical fashion, much of the fear and the misinformation will disappear. First of all it is caused by decay-producing fungi. The fungus, in the form of microscopic, threadlike strands, permeates the wood and uses parts of it as food. Most tree-attacking fungi quit after the tree has been cut. Very few attack lumber, and these only do so if conditions are favourable for their growth.
Needless to say, brown rot is one of them. Four basic requirements are needed to produce a good crop of brown rot.
First, the temperature must be between 50° F and 90° F, the higher end being ideal.
Unfortunately, this is the temperature range that humans find to be ideal, too.
Next, there must be oxygen. (Waterlogged wood doesn't decay because there is a lack of oxygen).
The third factor is moisture content.
As long as wood has in excess of 20% moisture content, the fungus can grow. This is why lumber in new houses is stipulated as being 19% or less moisture content.
The final factor is food.
Especially delicious to a fungus are spruces, elms, poplar and hemlock, those woods we are most likely to find in basements and crawlspaces.
So to avoid rot, make sure these conditions don't exist.
The good news is that eliminating any one of them (the one to focus on is moisture content) will usually control or arrest the fungal growth.
Unfortunately, the spores just become dormant, and can stay dormant for years, waiting for the right conditions to return so they can enjoy the good life again.
If the conditions which caused the growth are eliminated there should be no further problem.
But the wise homeowner would remove all of the infected wood from the building.
Another key question is how much strength loss will the rot cause?
Laboratory tests show that strength loss is a function of weight loss in the lumber.
For instance, if the wood has lost just 10% of its weight from decay, strength losses may be expected to exceed 50%! But this small amount of decay is NOT observable to the eye. By the time we can actually see the decay - or dig a probe in an inch or so, the strength reduction is much in excess of 50%.
If you are living in one of the "century old" homes with 10" – 12" trees as joists you have strength to spare.
Keep it that way by eliminating all possibility of rot.
If rot has begun, it is likely caused by a damp or wet basement. Remove the source of water, vent the area to dry it during the non-heating season, and mechanically remove the rot.
Remember--if conditions favourable for fungi growth to re-develop, a great deal of damage can be done in very little time.
Gone for the most part are the trunks, boxes and racks of outmoded clothing. Attics used to keep kids (and adults) occupied for hours, nosing around in discarded items and family history that often went back decades. The musty smell and diffused lighting helped spark the imagination of generations of kids.
Judged by those standards, today's attics are inaccessible, boring and unstimulating. But they still tell stories. The characters tend to be shadowy, but the most common plots centre on neglect or abuse.
To determine neglect, the attic owner (a contentious issue where a husband and wife are involved) should do the peek test. This test is based on the assumption that we have enough insulation (R32-R40) to keep us warm in winter and cool in summer.
On one of the hotter days in the summer we should peek up there to assess the temperature. The attic air space should ideally he the same temperature as the outside air. Too hot means that the heat will radiate down into the living quarters, often rendering them unbearable. The solution, more venting, can usually he accomplished by replacing one of the fixed roof vents with a wind driven turbo vent.
The second phase of the peek test should be done on one of the coldest days in winter. The attic passes if it looks the same as it did in the summer. We do not want to see hoar frost, icicles hanging from roofing nails, or other signs of condensation/sublimation. Should the attic display these conditions, or look like an ice palace as the worst do, this too can be solved by more insulation/ventilation.
The abuse usually shows up about the same time a handyman tries to vent a steamy bathroom into the attic, but builders can be guilty too. A 5 year old house inspected last week had 2 exhaust fans into the attic, both buried under fibreglass batts, both installed by the builder, and missed by an inspector. Similarly, a recent inspection of newer townhouses in Barrie revealed both laundry room and dryer vents exhausting into the attic. Mould and mildew were being produced in varying degrees, and rot was beginning in one attic.
Attic-destroying moisture is easily prevented. Simply use insulated ducting to route exhaust fan air through the attic and out the roof or gable end with the appropriate vent. Dryer vents should never be in the attic. Also, make sure the attic hatch is snugly fitted, insulated to the same R value (rigid insulation fastened to the hatch is best) and resting on weatherstripping.
The neat thing about today's attic is that once you've remedied any abuse, and it has passed the peek tests, you should have nothing further to worry about.
Those who choose to ignore their attics risk the growth of mildew, which will eventually lead to rot. In these worse case situations, the shingles must he stripped, the rotted components removed and new material plus shingles installed. Ignoring your attic can cause thousands of dollars worth of damage that could easily have been avoided.
