Sealing air leaks

When my wife and I were at Death Valley in December in the morning it was 35 -40F. I would turn on the bathroom fan when I was cooking and could feel a draft on my feet coming from the grill on the floor under the bathroom door. I could also feel a draft coming from the cabinet under the sink when I would reach in to get pots and pans. When I got home I wanted to do something to cut down on the drafts. The previous owners had stuffed fiberglass insulation in the space under the bathroom to cut down on the drafts. I wanted to see if I could get some spray foam in there. There are 3 pipes that go thru the floor, the black water tank vent in the left hand corner and the gray water tank vent in the right hand corner and the toilet. I taped down to the floor of the trailer some rosin paper because using spray foam is messy. I had a good work light that I pushed into the space. I also had a mirror I could position under there because you cannot see anything thru the access hole. I only had one mirror and it would have been better to have 2 to work with. I had a 2 foot piece of vinyl tubing that I pushed on to the end of the spray nozzle that comes with the can of foam and taped it on just as a backup so it would not come off. I then taped the vinyl tube to a 1/8 diameter steel rod. A coat hanger would be too flexible. I bent a 90 degree bend in the rod to I could get the tube behind the pipes. I positioned the mirror so I could see the pipes while looking thru the access hole and bent the rod to fit around the things in the way. It is very messy and so you will need gloves. I had the whole box of gloves in the trailer with me because I was changing them all the time. I was worried at first at not being able to see very well as the foam flowed out of the end of vinyl tube. I would get it close and pull the trigger on the foam can and then look at the mirror. I ended getting a lot of foam balls floating around but after it dried it did work. The one thing I would change is use a different foam, I used what I had in my garage and it worked but it is hard setting foam and so in the future if I have to replace something it will be a pain to remove. My recommendation is to use the foam labeled for doors and windows it will seal just as well and is soft setting foam so very easy to remove.

The next air leak was the lower lip seal on the slide out. The top and sides seal very well. I am sorry I did not take a picture of the lower rubber lip seal before I started, you can see a lot of day light. What I did is add a second lip seal made from ensolite foam. It is rugged closed cell waterproof foam and can handle temperature from -20 to 160F and it makes a great gaskets. I had to remove the 2 access panels from the cabinet so I could access the area under the cabinets. I also had to remove the small storage box under the refrigerator. You have to take all the screws out while it is under the refrigerator to get the sides and front panel off. I cut a 3 inch wide strip of foam and added 1 inch double stick tape. I used the tape to hold the foam in place along the bottom of the slide out. I then cut a strip of oak flooring and screwed it to the wall to back up the foam so it won’t come off. Where the 2 rollers are, that foam is held on with double stick tape only. In the center where the metal hat section and rack gear are, I cut the foam to fit around the parts and it’s held in place with double stick tape.

Gray water vent pipe


Toilet pipe


Black water vent pipe


Foam gasket around the roller bearing


Cut out in the upper corner of the storage box


Other end of gasket under the sink


center section trimmed foam