Renovation & Design

ASK THE INSPECTOR: When fixing someone else's mistake, get it right the second time

QUESTION: I have a bit of a problem I was hoping you could help me with. I bought my first house approximately three years ago. The basement is finished and has a bathroom with a corner shower unit. Unfortunately, when the previous owners installed the shower stall, they did so over a window! Last summer I noticed the glass was starting to come loose and it is an old single pane window. With all these storms lately, the glass has come loose on one side, which allowed some snow to enter. I blocked the window with a board temporarily. How should I permanently address this issue since I cannot access it from the inside of my house?

Thank you. Nancy Barbosa

ANSWER: Fixing someone else's mistakes, especially when it comes to home renovations, can be a major pain in the neck. You are undoubtedly faced with this challenge in your home, but yours should not be too difficult a repair as long as you take a few things into consideration when attempting this job.

Improper or amateurish renovations are some of the most frequent and frustrating issues that come up during a typical home inspection. This is even more prevalent in recent years with "contractors" buying homes for a quick sale or "flip." There are even annoying hosts on television who attempt to show you how to buy a home and successfully flip it so you can get rich. In reality, most re-sale homes require more than just a little cosmetic touch-up and often buyers get in over their heads. I would expect the previous homeowner, in your case, may have become embroiled in such a situation, or simply didn't know the proper method to install the shower. The old window may have provided some natural ventilation for the basement, prior to the bathroom installation, but now has become ineffective. I hope the renovator had enough sense to at least install a properly vented exhaust fan after covering the window with the shower enclosure. Removing or covering up the window in that case would make sense, but it has to be done properly to prevent further problems.

Covering an older window when bathrooms are renovated is a common occurrence as modern rooms of this type should have mechanical ventilation instead. That can be provided by a single exhaust fan, central exhaust fan or heat recovery ventilator. The main difficulty, when this is attempted, is to nicely match the patched window with the rest of the exterior surface without it standing out significantly. When this is done in the main living area, siding or stucco has to be added, which can be tough to match. In your basement area, the method of covering the window from the exterior will depend on the exterior surface of the foundation or walls. This could range from fairly easy to moderately difficult, depending on the current condition.

It should not be that tough to remove the old damaged window from the exterior to allow proper patching and sealing of the area. This should probably be done in warmer weather and your temporary patching may last until the spring when this could be more easily completed. After the old window is removed, likely by breaking the remaining glass and unhooking or cutting the sash, patching the opening should not be that difficult.

If the existing frame or buck, which is embedded in the foundation wall, is in relatively good condition and not rotted, it can be left in place. It can be used to mount wood stops near the inside face of the foundation wall. After that, a piece of plywood, oriented strand board, or other moisture resistant sheathing, can be cut to fit the opening and fastened to the stops. Now that the old window opening is covering on the inside, installation of a few layers of extruded polystyrene foam insulation, cut to fit the opening and fill almost the entire depth, should be glued in place. Each layer of this insulation should be caulked around the perimeter, with proper sealant designed for use with rigid foam insulation, to prevent air leakage from the bathroom into the cavity. Once this is nicely sealed, the exterior portion of the old opening can be covered, ideally with pressure-treated plywood, which can be fastened to the outside portion of the old buck. If the old buck is rotten, it should be cut out and replaced by new treated wood secured to the foundation opening prior to installation of both layers of plywood.

If the foundation is bare concrete and there is a gap between the top of the opening and the siding above, painting the new plywood grey to match the foundation may be the easiest solution. If this does not appeal to you cosmetically, which is a definite possibility, you may chose to cover the plywood instead. If the concrete foundation has a parging coat, covering it may be a better alternative to simple paint. If that is your situation and desire, the plywood should be installed with a small recess inside the exterior face of the concrete which will allow building paper or Tyvec and metal lath to be secured to the plywood. Once installed, a scratch coat of mortar can be mixed up and troweled over the wire mesh. After this cures, a top coat matching the existing foundation parging can be adhered to the surface to blend in to the surrounding foundation.

Despite the laziness of the individual who did not properly cover the old window in the bathroom in the basement of your home, it may not be that tricky to remedy the situation. The main concern is doing a proper job of insulating and air-sealing this area to prevent condensation and mould growth behind the shower. The cosmetic aspects of this repair should also be taken into consideration, but may be relatively easily done to satisfy your needs and desires.

Ari Marantz is the owner of Trained Eye Home Inspection Ltd. and the President of the Canadian Association of Home & Property Inspectors -- Manitoba ( Questions can be emailed to the address below. Ari can be reached at 204-291-5358 or check out his website at


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