Thank you for taking time to read my letter during this busy season.
We purchased our first home last year in May and moved in August 1. As much as we love the house it has caused us grief. Against my better judgement, there was no house inspection. We would have not got the home given the hot seller’s market.
Upon moving in, due to our wet season, I inspected the basement for signs of water damage. Finding mould in the spare bedroom wall and carpet led to me removing the drywall and revealing a vertical crack by the window. After further investigation and recommendations from various “basement waterproofing” companies we found that our weeping tiles have shifted and thus are useless. Lastly, efflorescence is noticeable in some areas of the basement in the storage room. The remainder of the basement appears dry and intact.
My understanding is that up until around 30 years ago homes were built with clay weeping tiles. Do homes with clay weeping tiles often have problems with water in the basement? Secondly, is it absolutely necessary to replace the weeping tiles? It will cost us around ten thousand dollars to replace the weeping tiles around the house, cut 2 drains and waterproof the outside of the house.
Please share with me the importance of weeping tiles and how it will help my house. It would be helpful to hear an unbiased opinion in regards to our problematic basement.
While I receive many, many inquiries about water intrusion & leaky basements, most don’t ask the direct question that you posed about the function and need for weeping tile. That is an excellent question and I will explain their purpose and also address your other concerns, but will leave the issue of the hot market and passing on inspections for another time.
It is true that most older homes in our area did have weeping tiles made of clay, and later concrete, before the current plastic drainage pipe came into regular use. The name “weeping tile” was originally used to describe the short, cylindrical tubes used for this purpose. In older homes, these clay tubes were normally laid end to end on the clay soil outside the entire concrete footing, which is below the foundation walls. They were loosely connected to a series of the same cylinders that ran from these exterior tiles, underneath the basement floor slab, to the catch basin above the basement floor drain. The idea was that the small gaps between the weeping tiles would collect excess water from the soil around the foundation and create a crude pipe that would direct this water to the catch basin, to be drained away in the home’s sewer system.
For the most part, this system worked well for many years. Unfortunately, the life expectancy of this system had major limitations due to a couple of main problems. The first potential defect is that, due to soil & frost related movement, the individual tiles would shift and separate, allowing excess clay soil to work its way inside the tubes. This would normally cause partial or total blockage, rendering the system ineffective. Also, soil pressure often caused damage or collapse of the clay tiles or excess shifting due to movement of the soil below the basement floor slab or outside the foundation. Either way, most older clay weeping tile systems have become almost useless after several decades.
The only truly effective method of repair for damaged, older weeping tiles is removal & replacement. This does require digging the soil on the exterior of the home down to the footing. Once the soil is removed, the old tile can be removed and replaced with new perforated plastic drainage piping, which is continuous and should last indefinitely when properly installed. The benefit of replacement in this method is that the exterior of the foundation can be cleaned, any cracks patched and new damp-proofing installed to ensure that seepage is stopped.
The final part of the repair may be to replace the weeping tile below the basement floor slab. Once the exterior excavation is complete, it may be possible to flush out the excess clay and debris from these tiles if there has not been excess movement in this area. If the basement floor is badly cracked and heaved, or the weeping tile damaged, replacement will be necessary. This will require cutting and removal of long, narrow sections of the concrete floor to allow installation of new, non-perforated drainage piping. This final stage may not be necessary, but is critical to ensure the water drained from the new exterior part of the system reaches the catch basin or a new sump pit.
The final item to address is the requirement for this costly repair. The answer to this question will be reliant on several current properties of your home. If you have several foundation cracks or openings that are allowing excess water into the basement, or if the original damp-proofing on the outside of the foundation is badly deteriorated, complete excavation may be required. If there is only periodic seepage through one or two small vertical cracks under the basement windows, a less costly, partial excavation may be possible. Digging down around individual cracks, to allow patching & application of new damp-proofing may work, certainly in the short term.
The final item to address is grading & drainage in the yard around the foundation. If the soil is well built up around the foundation, providing a gradual slope to the street sewer system, and the eavestroughs are in good condition & extended well away from the home, functioning weeping tiles may not be critical. Many older homes maintain quite dry basements even though their weeping tiles have stopped functioning many years ago. Attention to good grading & water management practices may save you thousands of dollars in expensive foundation repairs. Unfortunately, if this has been neglected for several decades, major excavation & weeping tile replacement may be the only permanent solution to keeping your basement dry.