Old basmeent reno advice

H All,

This year, my resolution to finally get my basement “hobby room” done. So, queries and ideas on how to finish the basement.

The jist: Older house in Montreal Quebec Canada, built around 1952. No “French drain” that I know of, but is dry. The basement was finished; typical for the time I guess: Tiles directly on concrete floor, walls are concrete foundation with wood firing strips, and “finished” gyp rock on that. (The gyp rock has a “wood panel” print on it, and 1945 stamped on the back!)

The bottom 2” -4” of the gyp rock has obviously seen some water over the years., but the wood & nails seem OK, no rust.

There is, however a nice layer of white powder on the walls, typical basement effluence I’m told. Now, not on the exposed walls of the laundry side, just behind what was ‘finished’. I’ve vacuumed some up in a corner, and I’ve noticed it does come back after a while (observed over a year) There is a definite line of where the effluence starts, about a foot or two off the floor. The walls were painted prior to finishing, and needless to say, the paint is peeling off in some places.

As it is a small house, and a small basement, I want to keep as much interior space as possible. Ceiling is also low, so I don’t want to loose any height either.

My first query is the effluence. Should I worry? Do I have to dig a French drain?!

Walls & Insulating: should I gut it and go with pink foam board, firing and gyp rock? Or, can I keep the original firing, and just use “spray foam” and gyp rock” (Obviously the cheapest in cost & labour) Will the effluence be problematic for the spray foam? Is one spray foam better than another!?

Flooring: it was suggested a sheet of 1” foam over a vapor barrier, and ¾” floor ply on that.. And then whatever flooring I want..

Any thoughts, input, ideas, suggestions?! All I’ve found to date point to newer constructions, and once that are pristine & clean!

thanks!

paul

For an ultimate DIY system for insulating the basement I recommend to you that using sheets of stiff foam insulation applied straight to the base walls. Making sure to seal the seams with a house wrap tape.

Best Regards,

Hi:

In the houses we've owned I've done several basement rooms that I use for an office or a workshop. I'm not a professional, but I'll relate my experiences to you.

The first things I've had to determine are:
(1) How 'nice' did I want it to look? Was I going to show it to visitors or just use it to work in? Your answer to that question will determine a lot of what you want to do (and how much its going to cost you).
(2) What about water and humidity problems?
(3) What about heat?
(4) How much did i want to spend and how long did I want to take before it is finished?

I've found that settling those questions tends to make the planning a lot easier.

Now in terms of the specific items in your post:

(a) The white powder you see is efflorescence. It comes from the salts in the cement and is caused by water seepage or humidity. That plus the fact that you believe there have been water problems in the past would lead me to first address flooding, seepaage and humidity correction. In my current house, I had to instal a sump pump do deal with seepage from snow melt and a dehumidifier to handle a dampness in the basement. The sump pump (installed) was US$1,000 because I was new to the area (now I know who to use). Once you've solved any water and humidity problems, a muratic acid treatment will eliminate the existing efflorescence. The fact that the efflorescence is only behind the finished section seems to indicate you have moisture vapor coming through the cement. Efflorescence is harmless, but the causes need to be eliminated.

Solving the moisture problem can be difficult. I've had to install sump pumps, change the slope of soil near the foundation and install gutters in various houses. Even then a four or five day Atlantic storm can cause problems. Good luck.

(b) When I have enough height in the ceiling, I've installed a drop ceiling. When I don't have enough room, I have painted the ceiling. It looks great and eliminates a lot of dust. BUT, painting the ceiling and joists is a long, tedious task. Wear old clothes and a hat. The basement ceiling where I am typing this is painted white, but using a flat black also works well.

(c) I would install the rigid foam boards between the existing firing strips and cover it with moisture resistant drywall or cement board. I believe spray foam would cost more.

(d) I don't have any advice about flooring. In newer houses, we've just put down carpet. In older houses, I've just used latex stain. I would suggest that you don't put much money into a floor unless you are certain you've solved the water and moisture problem.

Are french drains usual to Montreal?

OK, to detail a little further.

Ideally I want to have it looked “finished” and warm[er] in the winters. White paint on gyprock is what I’m after, fluro lights in the ceiling, etc.. get it looking like it’s been worked on / updated in the last 20 or 3 0 years..

There is no water or moisture per say.. Just the regular humidity in a typical Montreal summer. (I did notice a hygrometer hit +75% relative humidity one hot summer day..) I guess I’ve tried to notice some moisture in the odd corner after a heavy rain fall. But nothing I would say is “wet” or “damp”. A little moist maybe, but nothing that would soak a paper towel. The water damage I mentioned on the bottom of the gyp rock I assume has been from occasional condensation, and the odd wetness over the last 50 years. I figured this is kinda to be expected..

I have been addressing drainage issues, new gutters, redirecting their draining, and ensuring a proper slope around the house (new landscaping).

I guess my main worry about the effluence is if I go with spray foam, or glue on foam board, how long before the effluence gets between the bonding, and creates a gap / void. Is this amount of effluence normal? What is a normal degree of effluence?

The floor slab does have some cracks, and is lifted slightly in one spot, but no major heaving or shifting. Putting a floor down is to even it out, to help warm it up a bit, and to avoid standing directly on a concrete floor for long periods. (ouch!)

So, opinions on what works, and what would be better. I’ve been told to do both, but is there something that would be better?

Looking for minimal cost & minimal work..

Woggatollla said:

OK, to detail a little further.

Ideally I want to have it looked “finished” and warm[er] in the winters. White paint on gyprock is what I’m after, fluro lights in the ceiling, etc.. get it looking like it’s been worked on / updated in the last 20 or 3 0 years..

There is no water or moisture per say.. Just the regular humidity in a typical Montreal summer. (I did notice a hygrometer hit +75% relative humidity one hot summer day..) I guess I’ve tried to notice some moisture in the odd corner after a heavy rain fall. But nothing I would say is “wet” or “damp”. A little moist maybe, but nothing that would soak a paper towel. The water damage I mentioned on the bottom of the gyp rock I assume has been from occasional condensation, and the odd wetness over the last 50 years. I figured this is kinda to be expected..

I have been addressing drainage issues, new gutters, redirecting their draining, and ensuring a proper slope around the house (new landscaping).

I guess my main worry about the effluence is if I go with spray foam, or glue on foam board, how long before the effluence gets between the bonding, and creates a gap / void. Is this amount of effluence normal? What is a normal degree of effluence?

The floor slab does have some cracks, and is lifted slightly in one spot, but no major heaving or shifting. Putting a floor down is to even it out, to help warm it up a bit, and to avoid standing directly on a concrete floor for long periods. (ouch!)

So, opinions on what works, and what would be better. I’ve been told to do both, but is there something that would be better?

Looking for minimal cost & minimal work..

Click to expand...

OK, with your criteria of minimal cost & minimal work, here is what I have done using the same criteria.

1) It's good if you don't actually see water problems. Just be certain of this. You wouldn't want to invest a lot of effort and then have a sudden flood.

2) We've had houses in northern New York and New England. Roughly the same weather area as Montreal. I've always found it good to invest in a good dehumdifier. Taking the dampness out of the basement seems to make it seem more like part of the house. Getting rid of the humidity will also help correct the efflorescence problem.

3) You can get rid of the existing efflorescence with a muratic acid solution. Just be VERY careful working with it. Use eye protection and gloves. Be certain you have ventilation. Suggest you 'Google' the subject for advice.

4)I've never seen efflorescence that could push out foam insulation. The worst I've had have been minor salt crystal growths.

5) You've talked about 'spray foam'. In the US, that isn't a usual DIY project. I've used foam boards between 2x4's without problems. When I used the foam boards, the fire code in our area required I cover it with drywall (which I think is your 'gyprock').

6) In our current house (which will probably be our last) we use the basement for my office area, the laundry area, a play area for our grandchildren and general storage. I've tried to do things as cheaply as possible. We're just a few miles from the ocean, so I got a good dehumidifier. The exposed joist ceiling is painted white (a lot of work) and the walls are painted white with foam insulation under drywall. The floor has a light tan lates stain that has proven to be pretty durable.
I painted the heating and water pipes bright colors and we softened the overall appearence with area rugs and by hanging prints on the walls.

7) I don't have any experience about the cracks and slight lifting in your floor. If it were my basement, I'd be worried and would get an expert's opinion. My son had a basement with a floor that was in bad shape on one side. He built it up with a top coat of concrete. He moved shortly after so I don't know how it lasted.

Anyway, good luck

BSI-003: Concrete Floor Problems —

BSD-012: Moisture Control for New Residential Buildings —

Be safe, Gary

When I have enough height in the ceiling, I've installed a drop ceiling. When I don't have enough room, I have painted the ceiling. It looks great and eliminates a lot of dust. BUT, painting the ceiling and joists is a long.

Once you do get the water and insulation problems solved, don't forget dehumidification. High humidity is natural in a basement and will show up later as a "musty smell" if you don't run a dehumidifier.

GBR said:

BSI-003: Concrete Floor Problems —

BSD-012: Moisture Control for New Residential Buildings —

Be safe, Gary

Click to expand...

Nice links GBR! Thanks! :

Be sure to add a dehumidifier or you'l get that musty smell everyone hates.