A great many older Fredericton basements have had water in them at some point. That on its own is not the problem. The problem is the difference between a basement where somebody dealt with it properly and a basement where somebody made it look dry for the spring market.
Telling those two apart before you make an offer is worth more than almost anything else you can learn about an older house here.
Where the water actually comes from
Nearly always from outside, and nearly always for one of a handful of reasons: ground that slopes toward the house instead of away from it, downspouts dumping at the foundation, a window well with nowhere to drain, or foundation drainage that has stopped working.
That last one is the expensive one, and it is more common than people expect in the 1960s and 1970s stock. The Government of Canada puts it plainly in its flood-prevention guidance:
Even if your home has a weeping tile system, it may not be operational since these systems can become clogged with soil over time.
Government of Canada — French drains, trench drains and weeping tiles
Weeping tile has a service life. On houses of that vintage around Fredericton it is frequently at the end of it, and nothing about the inside of the basement will tell you that directly. You have to read the evidence.
The signs I look for
Inside, in rough order of how much they tell me:
- Efflorescence — the white, chalky bloom on concrete or block. That is mineral left behind by water that has moved through the foundation. It is not cosmetic; it is a receipt.
- A sump pump that is clearly newer than the house, especially if nobody mentions it.
- A dehumidifier running in October. Not August, when everyone runs one. October.
- Everything in the basement stored up on pallets or shelving, with nothing sitting directly on the floor.
- Drywall or panelling cut and repaired in a neat horizontal line, twelve or twenty-four inches up from the floor. That is a flood cut. Somebody removed wet material to a straight line and put new material back.
- Fresh paint on the lower part of foundation walls, particularly if it stops at a line.
Outside, I am looking for the evidence that the job was actually done: drainage rock, dimple board and blue skin membrane against the foundation, disturbed ground around the perimeter, and grading that falls away from the house.
Dealt with, or painted over
This is the distinction the whole page exists for, and Health Canada makes the point better than I can:
Unless the cause of the moisture problem has been identified and solved, mould will reappear. Mould that comes back after cleaning is usually an indication that the source of moisture has not been removed.
Health Canada — Guide to addressing moisture and mould indoors
A sealed and painted interior wall, a fresh interior membrane, or a sump pump added on its own are all ways of managing water that is still arriving. Sometimes that is a reasonable decision, made knowingly. Sometimes it is a way of getting a house sold. The difference matters to you because you inherit whichever one it was.
Health Canada also notes the health side is not trivial: damp and mould are associated with eye, nose and throat irritation, coughing and phlegm, and may contribute to asthma, bronchitis and other respiratory infections, as well as eczema. The target range for indoor relative humidity is 30 to 50 per cent.
What the real fix is, and what it costs
When a basement needs fixing properly, the fix is all-new drainage on the exterior of the foundation — excavate, clean the wall, new membrane, new drainage layer, new weeping tile, backfill and regrade. In Fredericton that runs $10,000 to $20,000.
People ask why it cannot be done from inside for less. It sometimes can be managed from inside, but managed is the right word. Again, the Government of Canada is direct about it: “Managing water outside the home is most effective and may provide longer-term solutions” compared with an interior installation.
Properly dealt with, in my experience, means all of the exterior work plus a sump pump with a battery backup as the belt-and-braces. A backup matters because the storms that put the most water in the ground are the same storms that take the power out.
Before you spend that, though: start with the cheap things. Extend the downspouts. Fix the grading. Clear the window wells. A surprising number of wet basements are a gutter problem wearing an expensive disguise, and no contractor is going to talk you out of the big job if you do not ask the question first.
A local example worth knowing about
Fredericton is not uniformly at risk. Some pockets are, for reasons of geology rather than construction quality.
Silverwood is the clearest one. It sits on a hill that carries a great deal of water down toward the river, and it is common for houses there to have had water in the basement at some point. That is not a reason to avoid the area — it is a reason to check carefully and to price the risk honestly if the exterior work has never been done.
Elsewhere, the variable is usually the individual lot: where the ground falls, what the neighbour did with their grading, and whether the original drainage was ever any good.
The radon connection
Water and radon get into a basement by the same routes — the joint between the floor slab and the wall, cracks, and penetrations. It is worth knowing that New Brunswick has among the highest radon levels in the country, several times the national average, and that the province recommends every home be tested.
A valid radon test needs at least three months, so it cannot be a condition of purchase. Test in your first winter instead, and treat sealing work in the basement as doing two jobs at once. The rural and acreage guide goes into the water side, and the radon page has the testing detail and the costs.
What this means for your offer
- Ask directly, in writing, whether there has ever been water in the basement, and what was done about it.
- Ask for invoices. Exterior drainage work is expensive and people keep the paperwork. If the seller says the drainage was redone and there is no invoice, that is information.
- Have the inspector look specifically at this. Say the word drainage to them before they start.
- If the exterior work has never been done on a house that shows the signs, put the $10,000 to $20,000 somewhere — in the price, in the conditions, or in your own budget with your eyes open.
My rule on this one
I will happily buy a house that has had water, where somebody dealt with it properly and can show me. What I will not do is let it slide.
If a home has too many indicators of water intrusion potential, I will not let my clients purchase the property.
That is a stronger line than most agents will give you, and I mean it. A wet basement is one of the few defects that keeps costing money every year you own the house, and it is very hard to sell later to a buyer who is looking for the same signs I am.
Where to go from here
Older Fredericton houses tend to arrive with more than one of these conversations at once — aluminum wiring and oil tanks and insurance and fogged windows are the others that come up constantly in the same vintage. The buying guide covers what the rest of the purchase costs here.
Thinking about selling a house that has had water at some point? It is far better to deal with that on your own timeline than during somebody else’s conditional period. A free evaluation is the place to start.
Or call or text me at (506) 261-7373. I answer my own phone.
Sources
- Government of Canada, Public Safety — French drains, trench drains and weeping tiles, flood damage prevention
- Health Canada — Guide to addressing moisture and mould indoors
- Government of New Brunswick and Health Canada — radon guidance for New Brunswick homes
This page is general information from a REALTOR®, not an engineering or building-science opinion. Foundation drainage work should be specified and carried out by qualified contractors, and anything structural belongs with a professional engineer.
