Ground Water Infiltration in Underground Pex & DIY Foam Insulation

trehugr said:

A bad day. 3 inches of rain has found its way into the foam insulation from boiler shed to house. It poured into the basement all night. Bad. Will be digging up pex this summer and looking for a "fail safe solution" Those of you considering doing your own foam, or even contractor applied foam, be 100% positive your water table and drainage are good to go.

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What is the problem? water running along side the pipes or water soaking into the foam?
leaddog

I am curious also. Was the water hot/warm as it came in? If not, don't assume that the water got to the PEX. It is very possible that the water surrounded the foam, but did not penetrate it. It got into your basement because it found a path of least resistance along the piping as it entered the foundation. Check your temp drop between the house and the source. If water is at the PEX, you will see a substantial drop.

You are correct that proper drainage is key. Whether it's foamed pex in a trench, a copper water line, or a PVC waste line, if the trench fills hydrostatic pressure builds as well and water will find a way into the house.

I looped my pex up before entering the foundation at about 12" below grade to avoid this problem.

Sorry to hear of your trouble. :-S

In my experience, water and mice seem to find a way in no matter how careful you are. In both cases, it's hard to over-engineer your solution. Hope it's not as bad as it seems.

I'm getting ready to foam my whole line instead of my DIY method. But used some Tiger foam in my present PEX insulation attempt. In my limited experience using some foam in my first attempt I tend to agree with Jim K. If your foam contractor did a good job of surrounding your PEX, I'd be willing to bet the water found/created a path between the bottom and/or sides of your trench and the foam. Jim's suggestion is right on the money. I'd be willing to bet the water's not impacting the water temps from your boiler which will prove the above theory. Which I can imagine would be much easier to solve by making one low spot with some gravel or a better idea from the folks here. I'm chiming in because this problem had not even occured to me happening, but you can bet I will do Jim's idea of a higher level to get into the house or some type of small field. I expect others will give us both better ideas. But I'd be willing to bet it's a dirt to foam problem, not foam to PEX.

Trehugr is your entry into the basement lower than your shed? Fortunately the point mine enters the basement is the highest point of the trench. My holes through basement wall are only 2.25" because that was biggest bit my plumber guy had at the time. My insulator did not fill the hole so I used regular foam pipe insulation. I thought about but didn't silicone the gap between the PEX and the outer basement wall. Now I'm wondering if I should pull out the pipe insulation and still do it. He sprayed a big area on the outer wall but I wondered how well the foam would seal against the concrete wall. Maybe if you not losing heat which I would doubt you are, you could get by with just digging by the basement wall and adding some drainage there. I hope you find any easy fix.

like everyone said the water is probably following the pipw into the basement . I have my pipe turning up toward the house but not enough that big logstor pipe bends very little . I also have has some water runin along the pipe so I dug up the last few feet outside and packed in a bunch of hydrolic cement . Inside we put in hyd cement and now it gets damp but no water . Next I will caulk and paint with drylock an that should taske care of it.

I had a problem with water when I installed my lines to. I used 2 insulated lines in a 5" unperforated drain tile tube. I just stuck it up under my garage slab because there was a thimble of the same size poured into the concrete. When the ground froze the slab raised leaving a gap between the tube and the slab. When it rained, the water ran under the slab into my tube and down into my basement. About 5 gal/hr. To fix I jackhammered a 16" hole around the thimble and added a section of the tube around the pipes. I taped and siliconed this to seal, then encased all in 14" of concrete. I have not had any problems this year.
Doug

Might be able to stop the water with hydrulic cement. Worth a try if temps are ok .

trehuger,

Didn't you post pics of your install? If i remember, it looked like a hell of a good job. Sorry to hear of the problems. but keep us informed.

Since I'm getting ready to dig up and foam insulate I'm really interested in your problem. What I've seen done here is to support and separate the PEX lines so the insulation totally encapsulates the PEX. The way the Tigerfoam I used expands and bonds to the pipe I'm having a hard time visualizing how water can travel down your PEX.

How long is the underground run?

I remember talking with a guy who had the same problem. Seems like he had fairly heavy soil and about a 3 foot elevation drop to the house from the OWB and got water in his basement whenever it rained. His solution was to jump up out of the trench and go into the house above grade. He used Insul-Seal pipe with 1" pex in the trench.

Trehugr,

What time of the year did you do the foaming?Summer, Fall? Was the soil damp? The foam kits are great for smaller jobs but the are very sensitive to temperature, moisture. How far is the run from the house?

heaterman said:

I remember talking with a guy who had the same problem. Seems like he had fairly heavy soil and about a 3 foot elevation drop to the house from the OWB and got water in his basement whenever it rained. His solution was to jump up out of the trench and go into the house above grade. He used Insul-Seal pipe with 1" pex in the trench.

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Here might be your best solution reminds me of when we had trouble with water following in some fiber optic cable and we ended up doing the same thing.

Underdrain...gotta have it.

Some pics here.

http://www.forestryforum.com/board/index.php/topic,40760.0.html

If you are in a wet area you need something like Thermo pex or the Canadian made equivalent. You put spray foam alone in a ditch and it will soak up water like a sponge. It may take it awhile but it will happen. I have seem this first hand. Do your job right the first time..... It will save you money in the long run. You wont be sorry.