Crawl space encapsulation?

[Gomer pyle]

I have been having issues with standing water under my house. I trenched it to a French drain and got most of the standing water out. All of my insulation and duct work is saturated with water. I had a company come look at it and they recommended trenching, piping, and a pump to remove all the water coming in. Their thoughts are that it is seeping through the blocks of the foundation. Of course, they wanted to sell us on termite treatment and spraying for bugs. The last thing he brought up was fully incapsulating my crawl space.
Is incap needed? beneficial? I've tried to do some research on it and it sounds interesting and if the price was not so HIGH, I would probably go ahead and do it. If I just do the water removal will my insulation and duct work be ok? We are recovering from a ugly court battle from a previous builder and doctor bills from cancer, so money is not loose but this is the place we plan to stay for a long time so we want to repair it correctly.

 

[RNeumann]

You need to get and keep the water out. Right now the house isn’t so healthy with all that moisture down there.

Anything you can do to keep moisture away from the building will help- gutters, drainage etc.
The best solutions are done from the outside- seal the foundation and install drains (and pump if needed). But this isn’t cheap.
If you can’t do that sealing the interior walls and ground is a DISTANT second option. But to do it right it isn’t cheap either.
I’d skip the termite man for these repairs unless his business is an atypical termite company.
If I was on a tight budget and had an issue like yours I’d get all the standing water out with a pump. I’d have fans moving air under the house continually. I’d work on the outside to ensure every bit of water around the structure didn’t flow near the structure- downspouts would be directed at least 20’ away, sprinklers off etc. From their I’d figure out how bad the issue really is.

PS- are you sure you don’t have a water line or sewer line that is leaking under or near the structure?

Sorry this is all happening at once. This issue certainly doesn’t help things, nor is it an easy or cheap fix.

 

[4570Man]

You need to get the standings water out because i don’t think the encapsulation will handle that. I encapsulated my craw space and it makes a HUGE differences. You can do it your self for a lot cheaper than they want. I was quoted over 2k labor to do mine. I paid a guy I had working for me at the time do do the grunt work which took about half a day and another better part of a day to install the plastic. You really need 2 people to put down the plastic.

 

[Gomer pyle]

The house has adequate drainage per two different inspectors. All gutters run from 10-30 feet away. I have removed the standing water myself but it is still very damp. The moisture content in the floor joist was 16% Saturday. They both said that is ground water. My property is about 12" of red clay on top of blue limestone. Both companies stated that I should trench inside instead of outside with the last guy saying to drill through the block to relieve any pressure the water puts on the wall??? I do understand and plan to fix the water issue before I would incapsulate.

4570, when you say it made a huge difference, in what ways?

 

[4570Man]

In the living space of the house not very much. In the basement and craw space which are connected it’s much dryer and smells better. The basement stays around 45-50 percent humidity and doesn’t have any typical basement musty smell.

 

[jfh28]

first if the company is trying to get you to treat for termites and bugs I would run away from them as fast as I could......bugs are the least of your worries at this point.....your priority is the water and from what you have described it does sound like ground water......do you know where your water table is?......best way to find out quickly is to dig a hole outside if you have a backhoe attachment on your tractor and see where you hit water....then compare that level with the floor level of your crawl space......if its above it then there will be to much hydro-static pressure for any interior wall coating to withstand for any amount of time and you'll need to deal with it on the outside of the walls........the floor is more problematic.......ideally there would be a concrete slab with water stops in place but it's to late for that.......best bet would be a pumping system that intercepts the water table before it reaches the floor level.......but those pumps could be running constantly if the water table is high......ventilation in the crawl space is critical to keep the floor joists dried out and more importantly the mold from growing.....get the air moving through there and out of the crawl space.....mold will also be the biggest threat to the insulation depending on the type and if it's paper backed and also inside the ductwork.....the best advice at this point would be to consult with a civil engineer who is familiar with the soil types in your area......someone with experience in perc tests and soil tests......I'm really sorry you are having to go through this......Jack

 

[Deere Dude]

Agree with these folks. Check for water leaks and water table height.

I had a damp crawl space with water standing on an edge or two. During a heavy rain water would flow toward the house because of lousy grading. What worked for us was to bring in a couple loads of chert (crappy sandy gravely soil) and slant the ground away from the house. I raised it a couple feet in one corner where the crawl space door was. I poured a concrete entrance for the crawl space so fill could be raised in that area by 2 feet and still get into the crawl space.

I did notice that the joists were starting to mold a little bit so I left the door off for maximum venting. I fabricated a screen with supports etc so it is not possible for critters to get in or people can't step through. The molding stopped because of the nice draft going through but is closed in the winter.

Water leaks, water table, downspouts corrected, ground pitched away. Gotta fix it. Love Tennessee crawl spaces,NOT.

 

[Tractor Seabee]

I have been having issues with standing water under my house. I trenched it to a French drain and got most of the standing water out. All of my insulation and duct work is saturated with water. I had a company come look at it and they recommended trenching, piping, and a pump to remove all the water coming in. Their thoughts are that it is seeping through the blocks of the foundation. Of course, they wanted to sell us on termite treatment and spraying for bugs. The last thing he brought up was fully incapsulating my crawl space.
Is incap needed? beneficial? I've tried to do some research on it and it sounds interesting and if the price was not so HIGH, I would probably go ahead and do it. If I just do the water removal will my insulation and duct work be ok? We are recovering from a ugly court battle from a previous builder and doctor bills from cancer, so money is not loose but this is the place we plan to stay for a long time so we want to repair it correctly.

Read through this post. One important point I did not see. What is the relative land elevations around the foundations? If the water table (not just surface drainage) is as high as the bottom of your crawl space you have a serious hydraulic situation. Where I live these problems occur a lot as folks build their foundations at too low an elevation, build at the bottom of slopes, build in depressed land areas. Then surface water then ponds up. There are a lot of engineering variables to consider before you start spending money. Armchair engineering sometimes misses the most important issue. It is impossible to propose fixes w/o seeing the problem first hand. What has worked one place may not work or could make it worse at another place. You are planning to stay there a long time so get it right the first time. For that reason I will not relate my experience with a flooding basement that occurred several years after moving there.

My daddy always told me "always build on the high ground".

Ron

 

[4570Man]

Read through this post. One important point I did not see. What is the relative land elevations around the foundations? If the water table (not just surface drainage) is as high as the bottom of your crawl space you have a serious hydraulic situation. Where I live these problems occur a lot as folks build their foundations at too low an elevation, build at the bottom of slopes, build in depressed land areas. Then surface water then ponds up. There are a lot of engineering variables to consider before you start spending money. Armchair engineering sometimes misses the most important issue. It is impossible to propose fixes w/o seeing the problem first hand. What has worked one place may not work or could make it worse at another place. You are planning to stay there a long time so get it right the first time. For that reason I will not relate my experience with a flooding basement that occurred several years after moving there.

My daddy always told me "always build on the high ground".

Ron

Agreed site drainage is very important. I had a guy have me pull up a bunch of bamboo because he thought the bamboo roots were making channels in the dirt for water to flow in. The fact that his house was a foot lower than the road which has a significant amount of water running in the ditch line that in a hard rain overflows the bank and then runs towards his house and then erodes the foundation as it run along the back of the house didn’t mean anything to him. My suggestion was put a bigger culvert under the driveway to minimize the overflowing the bank problem and bring in dirt to bring the slope away from the house and bury a culvert to drain the water down the hill away from his house. “ nah that sounds expensive, let’s just pull up this bamboo” I’m sure it fixed the problem. Until it rained again...

 

[RoyKing]

You could be screwed if your house is in a low spot and they didn't raise it enough. When I rains hard where does the water run from and too.

 

[ededic]

Pictures would help the armchairing considerably.

 

[Gomer pyle]

A little history behind the house (as I've been told), the house was moved here in '93, and then was renovated in '17. I know the foundation has been here for 25 years. The house sets on the highest point of my property. I'm being literal when I say all I have to do is dig down 12" to get to bed rock. I have a place outside(water cutoff in a underground box, box sets on top of solid rock) and when it rains heavy, the box is full of water to the top. So, I believe some of the water is seeping through the block and some actually just coming up through the ground. I climbed under the house a few months ago to move TV lines for the wife and found the standing water, so I know this has been going on for years, I trenched to the lowest point of the house and added a French drain. I will try to get some pics this evening if I get off work in time. Should I open my vents? I closed them to keep pipes from freezing.

 

[ddbackhoe]

A little history behind the house (as I've been told), the house was moved here in '93, and then was renovated in '17. I know the foundation has been here for 25 years. The house sets on the highest point of my property. I'm being literal when I say all I have to do is dig down 12" to get to bed rock. I have a place outside(water cutoff in a underground box, box sets on top of solid rock) and when it rains heavy, the box is full of water to the top. So, I believe some of the water is seeping through the block and some actually just coming up through the ground. I climbed under the house a few months ago to move TV lines for the wife and found the standing water, so I know this has been going on for years, I trenched to the lowest point of the house and added a French drain. I will try to get some pics this evening if I get off work in time. Should I open my vents? I closed them to keep pipes from freezing.

Dont panic, but you gotta get things dry down there before mold gets a foot hold. I fully suspect the foundation drain is either plugged up or non-existent. I would dig up and repair or install a new perimeter drain first (inside or outside). Get things dry, then you can go back and see what else needs to be done. Insulation and duct work can be dried out, but it will be a fairly slow process. This whole thing will take a considerable amount of time, but not a considerable amount of money if you tackle it one piece at a time. Even better if you can do the majority of the work yourself. Mold remediation (if necessary) is time consuming but can be a DIY project too.
I would probably put a fan or two down there to blow the damp air out.

Footing Drain Pipe | Building America Solution Center
How To Remove Mold: Mold Remediation — The Family Handyman

 

[GLyford]

You say the house is at the high point, and bedrock/ledge is a foot down. Do you have enough slope on the property to run water from a perimeter drain set right at/on the bedrock (either inside or outside the house) and still slope it down and out to daylight somewhere further away from the house? If your property slopes less than a foot then you are probably looking at some form of pump. Do any of the surrounding properties slope away enough that water brought to the surface have somewhere to go? If everything around you is higher you are kind of stuck.

Are some or all of the neighboring properties above yours? Could be uphill groundwater following the rock surface downhill. At worst, you have some sort of artesian spring...

 

[nikdfish]

Our place had crawl space humidity issues during the summer. No obvious wet spots or soggy ground, just tremendous amounts of condensation on the HVAC system sheet metal. Mold was beginning to show on some joists. Open foundation vents did not help as humidity is pretty much an all summer thing in NC.

We did the encapsulation for the full crawl space area + a blower to pull a negative pressure from the covered ground (think radon abatement). It was a pricey install but eliminated the condensation issue. Humidity now tracks pretty closely with humidity in the living spaces. A side effect is the HVAC guys really like the work space around the system now . Since our "crawl space" actually has 6' head space in some areas, the encapsulation has made for a nice clean storage space for some boxed items.

The blower has died a couple of times, but each time it turned out to be something I could fix. First time was just a piece of resin trash from manufacturing that broke loose & jammed the motor, the second time was a capacitor that cooked & a replacement had it up & running again.

 

[Handloader109]

The inspector says you have adequate drainage, but if that were true, you wouldn't have standing water. Water is coming into that area from somewhere. Better drains around perimeter. If walls to the bedrock, then inside the crawlspace and break through to drain.

 

[Budweiser John]

We solved a similar problem by installing 4” perforated drain tile around the permiter walls on the inside and terminating the down stream end some distance from the house.
We then covered the entire crawl space with 4 to 6” of pea stone and on top of the pea stone laid a heavy plastic vapor barrier and taped the seams. The vapor barrier extends up the permiter walls about 6”. The permiter walls were then covered with 2” styrofoam insulation board that overlaps the vapor barrier and is glued to the cement blocks.
The pea stone acts as a drainage plain and although a huge gut busting project to bucket the stone into the crawl space, it solved solved the problem.

As an aside, to reach the far corners in the crawl space we cominderred my son’s snow saucer and by putting a rope on each handle were able to put a 5 gallon bucket of pea stone on it with the guy on the inside pulling it to the dump site and the guy doing the filling pulling it back. Beat the heck out of trying to carry a full bucket while waddling along on one’s hands and knees.
B. John

 

[ddbackhoe]

huge gut busting project to bucket the stone into the crawl space

As an aside, to reach the far corners in the crawl space we cominderred my son’s snow saucer and by putting a rope on each handle were able to put a 5 gallon bucket of pea stone on it with the guy on the inside pulling it to the dump site and the guy doing the filling pulling it back. Beat the heck out of trying to carry a full bucket while waddling along on one’s hands and knees.
B. John

Yes,it is. The sled was a rather clever helper, I liked that one.

 

[dmottv]

....I'm being literal when I say all I have to do is dig down 12" to get to bed rock. I have a place outside(water cutoff in a underground box, box sets on top of solid rock) and when it rains heavy, the box is full of water to the top. So, I believe some of the water is seeping through the block and some actually just coming up through the ground. I climbed under the house a few months ago to move TV lines for the wife and found the standing water, so I know this has been going on for years, I trenched to the lowest point of the house and added a French drain. I will try to get some pics this evening if I get off work in time.....

A friend has a camp in VT with a similar situation: ledge at shallow depths, 1 to 2 feet, the soil is generally wet and saturates during rain events. The camp is on a bit of a slope. The groundwater and rain runs along the top of the ledge underground. He trenched down to the ledge on the uphill side and around both sides to an outflow downslope, laid perimeter drain pipe and filled with stone. That has solved some of the problem. The soil inside the perimeter trench area and under the camp is still somewhat wet, I suspect it is traveling through fissures in the ledge. Being a seasonal camp on a pier foundation, he does not have as tough an issue as you though. I think the next part of a solution is to grade a slope under the camp and layer with a depth of stone to act as a drain plane out the lower end. That is a slick plastic sled/toboggan idea! Good luck with it.

 

[Budweiser John]

ddbackhoe, thanks. Necessary is the mother of invention. No need to work any harder than necessary.