They call it a rubble foundation for a reason

By Charles Weiner


You cannot believe your luck! It’s your first time buying, and an affordable house becomes available in no less than the Glebe. The owner has a building inspection report, and there are only minor repairs listed. You discuss with your partner and decide to put an offer in at the listed price. There will be other buyers for certain, and this is one opportunity you cannot afford to miss out on. A day later, your agent calls and tells you that your offer has been accepted!

We are witnessing a great change of occupancy in the Glebe. Many owners are now retired and deciding to downsize and sell their homes. This is a wonderful thing for young families and individuals who wish to be part of this dynamic community. The problem is that some homes being sold by owners who have lived there for 40 years are no longer the home they originally bought. No problem if you happen to have lucked out or did your homework and bought a house with a stone foundation. This unfortunately cannot always be said for those who purchase a home with an aging rubble foundation.

When rubble foundations were built, Portland cement was at a premium. As a result, not enough of this bonding and hardening agent was added. So, years later, much of the cement has now leached out of the walls.

Many people are unaware of the degradation until one day, after prolonged rain, they find scaling from the wall on the floor, sitting in a puddle of water. If they are responsible, they call an expert to evaluate the situation.

It must be said that in half of rubble foundations, the owner has several years to save money before beginning the process of fixing the walls. In another third, costs can be spaced out over two-year intervals by completing one wall at a time.

Now, the unfortunate part of this story is the remaining 20 per cent of owners. In these cases (as recommended by a structural engineer), a complete repair must be done. That requires enveloping the exterior of the foundation walls in concrete and a moisture-proof insulation barrier. This process may need to be continued on the interior of the foundation walls as well. In most cases, the price of repair is so exorbitant that a new owner cannot afford the procedures needed to protect the structural integrity of the dwelling. That is why it is of paramount importance that you consult with a structural engineer or a structural expert who can do a proper foundation inspection before you purchase a home with a rubble foundation.

If you have any questions or need your foundation inspected, please do not hesitate to call. I am a structural expert, and the inspection is free.


Charles Weiner is an Ottawa structural expert and foundation repair specialist. He can be reached at 613-915-8377 or at


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