What's going on in my basement?

[kTHREE]

Hi everyone, soon to be first time home owner!
Sorry not garage related, that's coming soon enough.
Just in the final stages of closing on my first home and I've come across something I can't quite figure out in the basement.

In 2010 the basement in the 4 level split has its drain tile redone around the inside perimeter, and I'm speculating around the same time they applied poly to all the surfaces of the surrounding block. Located in MN if region specific.

What I can't figure out for the life of me is why?
I mean besides a whole lot of strangeness going on with this house anyhow. Most everything I read says this is not a good way to go about this. I pulled a small section down and everything was dry to the touch, no condensation anywhere.

We plan on framing the walls, at least in the back corner for my bunker/office to start.

Would the consensus be to pull down the poly, apply foam board to the block then frame over that leaving an inch air space between?
What would be your plan of attack?

 

[readhead]

May be a vapor barrier or part of a radon exhaust system. Is there a constant running exhaust fan?

 

[kd3pc]

Welcome to waterproofing 101.

This method is used a lot to waterproof a basement that has water infiltration...In my experience it is an expensive solution that works sometimes. My younger brother bought a home that the 6" cut was made around the entire inner perimeter, that concrete was removed, dug down and placed drain tile and then back filled and repoured the concrete. All that drain directed water to a sump pump in the lowest corner and his basement has been fine since...10-12 years later. Previous owner spent 10% of the cost of the house to get a dry basement/lower split....$18-20K for the whole project.

As to removing or redoing it...may be wasted effort - it all depends on what your thoughts are on doing things after the fact.

Others with more experience will chime in, I would leave it unless you are sure the boards will be better and drier than this

 

[kTHREE]

May be a vapor barrier or part of a radon exhaust system. Is there a constant running exhaust fan?

Nope no radon mitigation in place, had it tested as was around 1 pCi/L, IIRC the max is 4 before something must be done.

Welcome to waterproofing 101.

This method is used a lot to waterproof a basement that has water infiltration...In my experience it is an expensive solution that works sometimes. My younger brother bought a home that the 6" cut was made around the entire inner perimeter, that concrete was removed, dug down and placed drain tile and then back filled and repoured the concrete. All that drain directed water to a sump pump in the lowest corner and his basement has been fine since...10-12 years later. Previous owner spent 10% of the cost of the house to get a dry basement/lower split....$18-20K for the whole project.

As to removing or redoing it...may be wasted effort - it all depends on what your thoughts are on doing things after the fact.

Others with more experience will chime in, I would leave it unless you are sure the boards will be better and drier than this

That sounds like what they did as well.

Yep there is a sump pump in the corner by the washer/dryer, also dry as a bone. And the house is built on the top of a hill as well.
We are stumped, the only thing we can figure is if they were dumb about the downspouts or something. Seems like the went through an awful lot of work if it was that simple though.

Maybe just frame and fill with unfaced insulation?
Doesn't mix well with everything i've been reading that says the vapor barrier should be on the warm side rather than the block...?

 

[Milton Shaw]

I would wonder if there were cracks/gaps in the walls that are hidden by the plastic. It's on the wrong side if you insulate and I would think it should be removed and placed on the warm side of the wall. There are a lot of opinions here just though I would give another. You could check with previous owner and find out what it was done for. Might save a lot of money and work to make a phone call. The sales agent would not have any knowledge of what was done but should be able to get the previous owners information if it is not on your deed.

 

[ssdave]

Ask the previous owners what the purpose was and their reasoning. I'd rather know what they were thinking and what potential problems they were solving, rather than guessing. It may be years before the particular problem they were trying to address recurs, so it's best to know what it is before you cover anything up.

Real estate agents try to keep buyer and sellers from communicating to keep liabilities down. Personally, when I sell, I write up everything I know about the house, and include it in a notebook that has all the warranties, instruction manuals, etc from the house. I want the next owner to have all the information available to work from. I also give the new owners my telephone #, and tell them to call me if they have any questions or doubts. I answered a question just last week about the house I sold 6 months ago; the new owner was doing some changes and wanted information about how some of the electrical was run.

 

[58Yeoman]

I sold my last house in '08, and it was built in the 30's. The poured foundation leaked like a sieve and was crumbling. I tried cleaning the efflorescence and painting with DryLock twice. Didn't work. When I went to sell the house, I had a company come in and put in drain tile on the two walls that were leaking. They installed a sump pump and tile. On the walls, they installed ugly rubber sheets about one foot up the walls to catch the water that leaked in and directed it to the sump/tile. The new owner would have to put up studs to cover it. I don't know if they did or not.

 

[lampare]

All the white sheeting reminds me of a cannabis grow
operation???

 

[Bob275]

That's definitely waterproofing, don't remove it. I bet it goes right down into the perimeter floor drains. That's an expensive option around here.

 

[jmarkwolf]

Get a pre-buy inspection.

 

[theoldwizard1]

The poly is there so that IF THERE IS A LEAK it will run down into the internal weepping tile.

 

[kTHREE]

So then can I frame right up to the poly? Should I leave an inch airgap?
Or should I get someone that knows better to take a look.

 

[kTHREE]

Oldwizard and bob, you were right.

Finally heard back from the original installer that did the drain tile.
It is integrated into the drains for waterproofing. Even better it's warrantied for life and transferable to the new owner (me).

Was advised to frame out an inch from the wall and use a non faced insulation in the walls. Also to use drilled floor anchors instead of any powder actuated nails.

 

[martyre]

a cannabis grow
operation?

 

[Lunker]

So then can I frame right up to the poly? Should I leave an inch airgap?
Or should I get someone that knows better to take a look.

leave an inch or 2 and stud and insulate

This is waterproofing that is designed to catch water through the wall or over foundation it directs leaks into the tile.

 

[ard]

Buy a house with a properly drained foundation; properly (exterior applied) foundation waterproofing ....

 

[kTHREE]

Reading > the last three posters. Already got all the answers from the builder that did it.