Comments on: Save Energy and Money – Insulate your Crawl Space Properly

By: Susan

Susan — Mon, 10 Jan 2011 13:50:31 +0000

I put a temp/humidity digital probe down in my crawl to see what was going on. You can find them cheap on the net. The temp stayed about 58 (Maine) in the winter and the humidity was well over 75%. The house was drafty and some of my shoes mildewed in my closet. I has the crawl professionally sealed and installed an air conditioner unit (dehumidifier). The temp stays the same but the humidity is a pretty much a constant 40%. The crawl has a pea stone floor which was covered. I tried laying 8 mil plastic over it some time ago but it didn’t keep the moisture down. The moisture is the killer. Nothing can grown under 50% humidity. Heck, I can store anything down there now, it looks and feels like a giant clean room.

By: Denise Lawrencwe

Denise Lawrencwe — Sun, 09 Jan 2011 11:57:37 +0000

I bought a 1952 home with a crawl space and the vents on one side are sealed with dirt. Do I need to open these? I live in an area that is cold in winter (fear of broken pipes) and hot in summer. I was told to place a vapor barrier on the ground, but they said nothing about removing the dirt. My contractor has removed it (dirt), but I DON’T think it is correct. HELP! The brick that keeps water from getting in this space has been removed (is water going to run under the house?).

By: Hawk

Hawk — Sun, 05 Dec 2010 04:52:44 +0000

Greetings….

I have a crawl space. So if I understand. The vents that are located on the foundation wall, i believe one in the front. If there is another one it is in the back of the house under the deck.

I need to close that vent, and it will kill the draft I am getting in the cold months?

I am also wondering is there a product that I could lay down on my sub-floor. We are about to replace our carpet in the drafty rooms. It is time for it to go. So we are going to get a carpet pad with an insulation value of 2.1. The cost is real good as well, so we are going to go for it. While the existing carpet is up, I am going to screw down some loose spots on the sub-floor. I would like to know is there a product that I can use as a membrane to either roll on or spay on the existing plywood sub-floor. It might be some type of rubber based product. I want to use something that will protect in the winter, and in the summer not smell up the place. And has a high temperature point to it.

Any information would be great

Thanks

By: Ken

Ken — Sun, 28 Nov 2010 21:56:32 +0000

I have an addition to my house that has a crawl space under it. It is open to my basement by the way of the old basement windows. The floor above the crawl space is cold how should I go about insulating the area of the crawl space. Insulating the floor joist or by fully encapsulating.

By: Michael G

Michael G — Wed, 25 Aug 2010 10:24:26 +0000

I have a situation with a customer of mine that has major moisture issues under his house. Add an air handler under a house with floor insulation and you will have a mess. I guarantee you that. The only way to completely get rid of moisture under a house is to totally encapsulate underneath and have a dehumidifier installed.Its costly, buy effective. The combination of thick schrubbery around a house, and an air handler blocking air from entering and escaping from under a house, will cause insulation to act as a sponge when humidity rises and dew point is met. With the system off I read 72% humidity under this house. When the system turned on- humidity rose to 85% in a matter of seconds. In my opinion- dont install an air handler under a house or have floor insulation installed if you live in the south. I have seen too many insulated floors rot under bathroom and kitchen cabinets. The idea of having floors insulated where humidity levels are high is long gone and shouldnt be done. The insulation will eventually fall from between the rafters onto the ground anyway- even if installed correctly. If air cannot cross breeze under a house without any obstruction such as ductwork or an air handler- you will experience major moisture problems. I cant stress enough. Dont install floor insulation.

By: Susan

Susan — Fri, 12 Jun 2009 16:40:17 +0000

I read all of these comments and have been through all the gyrations. I’ve owned a ranch style home in Maine since 93; it was built on ledge and has a 4 foot crawl. The insulation was sopping and you could have floated a canoe under it along with adding fish. Fixing the broken sump pump fixed the water problem, but I will had an open pool of water in the crock.

I tired a dehumidifier, plastic, fans, sealing the vents opening the vents, all to know avail.

I bit the bullet and just had a fully encapsulated system installed with a submerged sump pump with battery back up. Guess what, no cold drafts in the house this morning! First time in 16 years. It was worth every penny. The vents were completely seal over, the foundation walls were covered with 2″ dense blue wall insulation and then covered over in a heavy lining, the pea stone floor received what I call a waffle pad and a 20 mil liner. the joist bays were sealed with 2″ spray insulation, and the crawl space plug was removed and a thick plastic sealed panel was installed that is weather stripped lined.

I wish this system would have been around back in 93, I have spent more TIME and tons of money trying to slay this beast. I am going to monitor my energy savings to see what cost savings are realized.

By: denise

denise — Tue, 09 Jun 2009 17:06:30 +0000

Regarding the post from the person who lives in the south (back a couple of years ago unfortunately). You said you installed a dehumidifier and closed the vents…would I still need to install the vapor barrier is I did this? Where can I get the dehumidifier? I live in central Texas and it’s VERY humid here.

By: denise

denise — Tue, 09 Jun 2009 16:59:05 +0000

Did anyone comment on Glen Boehme’s April 26, 2009 posting? I have the same issue with my old house…I can’t get in there to install a vapor barrier – do I have to remove all the floors in my house to do this???

By: Glen Boehme`

Glen Boehme` — Mon, 27 Apr 2009 02:57:11 +0000

The crawlspace under half my house is only about 15 inches to 6 inches .Not enough room to crawl under.the other half (an addon) is about 3 feet.I have vents that open and close all around the house.I am told that lying plastic on the ground will cause vaper to condense till you have puddles of water on the plastic.I used insulation in all vents untill I replaced them this year.Last spring I took out the insulation and found one corner (under an unused room) was so wet I ran my hand up to the flooring and came away with water in my hand.I had to replace the 2×6 that lies on the cement foundation and some of the flooring.I left the opening off to dry for a week. I checked and all had dried up . So what is the right way to insulate the crawl space? I am really confused.HELP!!!

By: Joseph

Joseph — Fri, 27 Mar 2009 01:56:14 +0000

“We now know that venting is not a great solution for keeping crawlspaces clean and dry. Indeed, venting will only help increase crawlspace moisture levels if the outside air is dryer than the air in the crawlspace, or when enough hot outside air enters and warms the crawlspace. New studies have shown that as air enters the crawlspace through the foundation vents and comes in contact with surfaces that have been cooled by the cold air in the ducts, the dew point is reached and condensation occurs. And when condensation forms on various surfaces within your crawlspace, you have the ideal environment for mold, mildew, and the accompanying problems they create in your home.”

Taken from Your Crawl Space.