Author Topic: Finishing Basement Project - Advice/Feedback needed  (Read 1513 times)

MrSal

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Finishing Basement Project - Advice/Feedback needed
« on: June 08, 2018, 08:34:03 AM »
So... After my kitchen renovation threads and backyard and deck projects, MrsSal and I are about to start renovating the basement.

Our house is a single family home, ranch style, from the late 50s or early 60s.

We have cinder block basement in Central PA. As far I know, we don't have water problems in the basement. We have a french drain in the basement in its perimeter or at least 2 walls connected to a sump pump.

Yesterday this happened:



We got a good deal for it saving us almost 60% on the insulation in rigid foam... this is 2" XPS. Even though it's reclaimed, it's in very good condition actually... and the guy was nice we gave us an extra 8-10 boards. All in all about 14$ per the equivalent 4x8 xps sheet.

Now my question is on how to structure the outer walls of the basement. I have researched for so many hours and there is so much conflicting information it's hard to decide on what...

Ive seen people recommend moisture barriers, others saying they dont have a place in basements... others for vapour barrier others not for it...

My idea was to put the XPS foam against the cinder blocks and tape the seams with a good quality tape. As far I was able to see, because I have 2'' panels I shouldn't need a moisture barrier since the XPS at 2 inches acts itself as a moisture barrier. Then, on top of XPS just build the walls with studs, perhaps add extra insulation such as rockwool or just leave the gaps empty and apply a vapor barrier and then drywall.

My concern is with the application of the XPS and the french drain at the edge... i do have cinder block so there are grooves in them although staggered... would this be enough if water comes in, to slide all the way down the wall to the french drain? Or, should I use some sort of dimple mat between the XPS and the cinder blocks? If I were to do the whole wall, this would get expensive... 1000$ just for dimple mat... I have seen someone recommend, to just apply dimple mat the first 6 inches from the floor in order to make sure the french drain entry is open...

Also, should I use Drylok paint on the cinderblocks? My wife says her mothers basement used to leak a lot! and once they did the Drylok paint all issues were gone... again, online I have seen contradicting information about the use of this... granted, we don;t have a wet problem basement ... sure it's a bit damp but i dont see any runoffs, however I will be doing the plastic sheeting taped to walls test in order to assess moisture. Our ground is sloped away the building for the most part, our gutters are working correctly and we do have the french drain sump pump as well ... no idea how the exterior foundation looks like in terms of french drain, gravel stones or any waterproofing... its a 50s-60s house.

Any feedback and advices would be greatly appreciated!

Thanks
« Last Edit: June 08, 2018, 10:41:12 AM by MrSal »

BudgetSlasher

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Re: Finishing Basement Project - Advice/Feedback needed
« Reply #1 on: June 09, 2018, 10:02:00 AM »
Basement insulation and drywall is on my radar (but several projects down). Our house is very different, built in the early 90's, poured concrete, and no internal drain or sump. But, I will tell you how I plan to tackle it in our house and perhaps you can take an idea from that.

My plan is to do 2 layer of 2" XPS, I will likely just use some low expansion great stuff to seal the cracks between the boards. To anchor it I plan on running furring strips across the foam board at 24" internals (likely left to right) which I will then anchor through the foam with masonry screws. Depending on the flatness of those furring strips and my need to run electrical behind the drywall, I will either attach the drywall directly to the furring strips or I will add a second set of furring strips running up to down (this will allow me to shim them level which each other and allow for wiring to run both up and down and left and right between the furring strips behind the drywall).

As far as your moisture question, I am afraid I cannot provide anything. For my situation (dry walls) my research points to sealing the foam to the wall. This will prevent air (with moisture) from circulating behind the insulation and condensing, which would likely lead to mold and air quality issues.

MrSal

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Re: Finishing Basement Project - Advice/Feedback needed
« Reply #2 on: June 09, 2018, 09:04:01 PM »
Yes my basement is dry as well ... only issue is a dampy smell typical of basements but i think is due to humidity.

Hmm... Using firring strips with masonry screws... how does this work? We are trying to keep water out of the house however, this way a person is puncuturing lots of holes in the concrete/cinder blocks... wouldn't plain glue be a better approach?

Your 2 sets of furring strips sounds like a good idea... especially regarding the ability to run wire after the fact vertically and horizontally...

Not sure yet regarding a vapor barrier or not... hopefully someone more experiencied will show up ... maybe paddedhat will chime in :)

BudgetSlasher

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Re: Finishing Basement Project - Advice/Feedback needed
« Reply #3 on: June 10, 2018, 09:37:36 AM »
Yes my basement is dry as well ... only issue is a dampy smell typical of basements but i think is due to humidity.

Hmm... Using firring strips with masonry screws... how does this work? We are trying to keep water out of the house however, this way a person is puncuturing lots of holes in the concrete/cinder blocks... wouldn't plain glue be a better approach?

Your 2 sets of furring strips sounds like a good idea... especially regarding the ability to run wire after the fact vertically and horizontally...

Not sure yet regarding a vapor barrier or not... hopefully someone more experiencied will show up ... maybe paddedhat will chime in :)

It may be different with block, but with our poured concrete the screw would only go about 1/7th of the way through the concrete. It shouldn't create a new pathway for water through our wall; I haven't seen additional water intrusion at any of the masonry screws that existed in the walls before we bought the house. Plus moisture wicks through concrete if the moisture gets into the concrete on one side (outside) and the other side is dryer (inside) it will come through, regardless of a few 1/4" spots where the concrete is 1" thinner.

If your original plan to build a wall inside of the foam board, there is still a need to attach a board to concrete (the bottom plate to the floor), which is likely best addressed with a concrete screw or nail.   

Plus in our case there is already a paint on water barrier on the exterior, a perimeter drain by the footing, and in some places (but not most) 3/4 foam board below grade.

lthenderson

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Re: Finishing Basement Project - Advice/Feedback needed
« Reply #4 on: June 11, 2018, 07:37:34 AM »
My idea was to put the XPS foam against the cinder blocks and tape the seams with a good quality tape. As far I was able to see, because I have 2'' panels I shouldn't need a moisture barrier since the XPS at 2 inches acts itself as a moisture barrier. Then, on top of XPS just build the walls with studs, perhaps add extra insulation such as rockwool or just leave the gaps empty and apply a vapor barrier and then drywall.

Also, should I use Drylok paint on the cinderblocks?

A good way to get a handle on moisture in your basement walls is to tape of square of plastic say two feet by two feet over a section of walls and check it after a couple of days. If you see moisture bead up between the wall and the plastic, you know your basement isn't sealed on the outside. If it doesn't, most likely it is sealed on the outside.

With 2 inches of XPS foam, I fall in the camp that a moisture barrier isn't necessary because that amount of foam should insulate the concrete walls enough that house borne moisture won't condense on the foam and act as a moisture barrier if the vapor is coming through the basement walls. If you go with an inch or less, then you may want to put a moisture barrier to prevent house borne moisture from condensing on the foam but it doesn't sound like this is your case. I absolutely would not put a moisture barrier between your stud wall and drywall. All that will do will create a humid cesspool for mold to develop in your stud cavity and rockwool insulation should your basement wall ever get moisture between the installed foam and the additional vapor barrier. Two vapor barriers are never a good thing. If your block wall is allowing vapor through, it is better to but the vapor barrier up next to the concrete surface and in this case, the foam should do that.

Drylok works as a vapor barrier but does nothing to stop or prevent leaks. Hydrostatic pressures are just too great for drylok to stop it and it says in the directions on the can that it will not prevent or stop leaks.

CowboyAndIndian

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Re: Finishing Basement Project - Advice/Feedback needed
« Reply #5 on: June 11, 2018, 10:27:18 AM »
...
Also, should I use Drylok paint on the cinderblocks?
...

Yes!

Once you finish your basement, if there are any leaks it will be hard to fix. Additionally, Drylok closes the pores in the concrete and MIGHT reduce any radon gas entering the basement.

I would highly recommend making sure that water does not enter your basement by doing the following
  • The grading around the walls of the basement is away from the house (1inch drop for every 10 feet or so)
  • Your gutters do not dump water near the basement walls, it should be about 10 feet away.
  • Make sure you have  sump pump and backup


Some other suggestions for your planning
  • Plan your basement so you have easy access to the mechanicals.
  • DO NOT use carpet in your basement. It is a mold-generator. Use Vinyl Plank, cork or laminate(last choice).
  • Set up a lot of lights. Basements are dark.

« Last Edit: June 11, 2018, 10:31:40 AM by CowboyAndIndian »

MrSal

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Re: Finishing Basement Project - Advice/Feedback needed
« Reply #6 on: June 11, 2018, 11:00:06 AM »
Yes I won't put carpet on basement. I hate carpet.

Most likely I will keep it concrete and/or just apply a leveling concrete in order to make it smooth.

All walls will be white in order to reflect more light...


So I will go with XPS, all really sealed up with good tape and caulk. Same for the sill cavities.

Use firring strips and/or just build normal wall with bottom plate being pressure treated.

Attachment of foam - XPS foam adhesive or mechanical fastening?


BTW, I guess I really got a good deal on that XPS even though it's used...  I got it for cheaper than cost of production. Out of curiosity I reached out a few manufacturers in China for the supply of 100 cubic meters of XPS ... and the cost would be around 100$ per cubic meter - which for a 8x4 2inch XPS is about 18$ per sheet ... And I'd still have to pay for freight + importing taxes ...
« Last Edit: June 11, 2018, 11:19:32 AM by MrSal »

Fishindude

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Re: Finishing Basement Project - Advice/Feedback needed
« Reply #7 on: June 11, 2018, 01:06:28 PM »
Google "metal zee furring with rigid insulation" and look at images.
This is how I would install the insulation, then the metal zee gives you something to fasten your interior wall material to.

MrSal

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Re: Finishing Basement Project - Advice/Feedback needed
« Reply #8 on: June 27, 2018, 12:27:20 PM »
alright... i am gathering all supplies I need so I can bring this to Lowes and go through their Pro Desk - you need 2500$ or more in order to do so ...

I know I can do coupons and probably get 20% off of the retail price but maybe I can get more savings by bulk shopping through their pro desk.

Here;s a list... anything else that I am missing? This is for a 45x25 basement ... so far I don't have planned any interior walls - still undecided if leaving it open space or not ... anyhow adding walls after the fact shouldn't be too hard.

Thanks


Swish

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Re: Finishing Basement Project - Advice/Feedback needed
« Reply #9 on: June 28, 2018, 11:02:10 AM »
Sounds like you have a pretty good handle on your project already. Here is the foundation wrap I used and picked up from the hardware store. Works great and is easy to install. I used it on the out the outer walls of my rental house and have had no water since. Cost $220 for a 100'x6' roll.
« Last Edit: June 28, 2018, 11:21:39 AM by Swish »

Swish

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Re: Finishing Basement Project - Advice/Feedback needed
« Reply #10 on: June 28, 2018, 11:15:56 AM »

My concern is with the application of the XPS and the french drain at the edge... i do have cinder block so there are grooves in them although staggered... would this be enough if water comes in, to slide all the way down the wall to the french drain? Or, should I use some sort of dimple mat between the XPS and the cinder blocks? If I were to do the whole wall, this would get expensive... 1000$ just for dimple mat... I have seen someone recommend, to just apply dimple mat the first 6 inches from the floor in order to make sure the french drain entry is open...


Your price for dimple board is really high. The foundation wrap I put above is a lot cheaper and does the job well. It comes in 6.6' and 8.6' rolls. If your basement is damp still with the recommendations from CowboyAndIndian it is most likely ground water. You should dig down to the exterior footing. Replace the weeping tile, put foundation wrap on outside then lay 4-6 inches of gravel. Then install new weeping tile, Dig out beneath footing to your sump and run weeping tile into/beneath your sump box. (this is a lot of annoying work but well worth it). Then put 8-10 inches of gravel over the weeping tile. Once completed your basement should be very dry.
« Last Edit: June 28, 2018, 11:23:33 AM by Swish »

MrSal

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Re: Finishing Basement Project - Advice/Feedback needed
« Reply #11 on: July 16, 2018, 01:42:47 PM »
You got to love Lowe's for their coupons and other promotions. I just ordered a bunch of stuff taking advantage of today's 10% for MyLowes members...

I ordered Drywall which above 20-30 gives me 20% off for bulk pricing.

Ordered the metal studs and track ... I also ordered a skylight and a clear glass exterior door for basement ...

Total it was 2108 for ALL of it but with their bulk pricing and the ability of stacking the 10% off today's promo + 10% off coupon I got it to 1220's !!

However, out of pocket I spent less... I have been buying gift cards at 10% discount ... so those 1220's only cost 1098 out of pocket!

Couple that with another 4% cashback on Ebates or any other online portal and thats another 50 off for a total of 1050$ spent!

Swish

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Re: Finishing Basement Project - Advice/Feedback needed
« Reply #12 on: July 16, 2018, 03:30:16 PM »
Congrats! Always feels good to save a few bucks. Do you have pictures of the project progress?

MrSal

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Re: Finishing Basement Project - Advice/Feedback needed
« Reply #13 on: August 13, 2018, 05:28:07 PM »
Yes a lot of money was saved due to that! Gotta love Lowe's discounts and such... I was able to beat their Pro quote by a large amount!

In other news, while I was away from the country we got hit by almost 14 inches of rain in about 5 days! To the point, where our basement window wells were filled with water and my wifes parents had to come to our house and pump it out and because the ground was so saturated it just kept refilling.

No water came into the basement at all I was told... and judging from it, the windows were well sealed since they were pretty much like aquariums ... no water got in even through the windows which is surprising!

Now that I am back I need to start putting the studs up!

martyconlonontherun

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Re: Finishing Basement Project - Advice/Feedback needed
« Reply #14 on: August 15, 2018, 03:42:39 PM »
My issue with my basement is I cut off the flow of air when closing off some rooms. This caused humidity/water to puddle in parts of the basement. Even if its dry now, I recommend getting a dehumidifier now just in case.