Air Leakage Explorations and Sealing

[Hercules]

Living in the Cedar Creek in WINTER makes one become very attuned to sources of air leakage. A few cold and snowy days turned me into a "air leakage hunter" and - WOW - was I surprised.

First, there are hidden air leaks everywhere! Not just poorly fitting slide gasketing (as I originally expected). Everywhere. While I am sure I am not the first to post on this topic, I thought I'd share my "hole" findings...

1. First BEFORE you go try to plug holes - FIND them all. Do them all at one time. Only way to get the most $ out of your can of Great Stuff or whatever foam you use.

2. Use the EXPANDING foams for big holes (and there are a lot of big holes.

3. Why do we use a 2-inch hole saw for a 3/4" pipe opening? I'm in the construction business and it never ceases to amaze me what dumb things we do in construction. Look under the kitchen sink - at the supply and the drain penetrations. Oh, you MIGHT find a cheesy plastic cap attempting to cover the holes, but the holes are still there. My drain line hole was so big I could put my hand in it! (That was also one of my pesky mice entry ports.). I shoved some steel wool down in the hole (to slow down the mice) and then used expanding foam to fill the hole. The area under the sink got a lot warmer...

4. I began to notice that every time I reach for a frying pan next to the stove the pan was COLD! Of course, you can't easily GET to the back of the stove, so the Braille method was used to find the hole (laying on the floor, reaching blindly behind the stove, finding gas lines and wires...). Yes, once again, a 2" hole for a 3/4" pipe. Straw on the end of the foam can, shoving the straw into the hole, pulling the trigger.... hoping that I filled it. FYI the next morning the frying pan handle was WARM!

5. Bathroom supply and drains. Same as kitchen. BIG holes. Foam.

6. The "cabinet" in the closet housing the water heater. BE CAREFUL HERE. My first inclination was to seal up all those cracks and holes. But there are WATER LINES in that cabinet, and I thought better to make sure it is sealed from the OUTside.

7. OUTSIDE. The bulb weatherstripping on the access doors is pretty good, but the doors them selves are also big thermal short circuits. SOME of them I could put some insulation against (I used some blue board, but other types would work. A little double sided tape would hold it in place until I really needed to get in there.

8. The BIG hatch under the bed in the bedroom slide is a BIG uninsulated hole. I raised the bed to gain access from the inside and pushed closely fitting foam boards up against the hatch door. Then I put our extra blankets
Up against the insulation to hold it in place.

9. Water heater access. This one is posing a problem. Of course, my water supply lines are there, O they are insulated and the hole into the Cottage is foamed. By the doors (side and rear) are uninsulated and a big source of cold... Still pondering how to fix them. Any ideas are welcome.

10. Probably the biggest leak... the slides. The bottom edge of the 3 slides rests on a piece of durable plastic - a "glide" of sorts - that is the only thing between the cold outdoors and my toes when standing at the stove or sitting on the couch. The floor at the edge of carpet at each slide is just COLD. (BTW, it snowed again last night.). I got some rope caulk/putty, thinking about trying to reduce the leakage there, but I have not done it yet. (Too cold to be crawling around under the unit...hahahaha). Most slide edges fit well to the unit, but a couple you can easily fit finger thru to the outside! I got some foam rope and fitted it into the edge from the inside, but there has to be a better solution.

PLEASE share your solutions to the air leakage issues!!!

Thanks,
Chris

[whj77372]

Sorry for the cold weather, I bet you wish you could be in Southern Florida for the winter and not NC?

[scottg985]

I have been in the process of the same thing on our 360PDK. The slide with the table and entertainment has a notch cut in the floor for the outdoor sink to slide in. The outside slide seal is cut for this and fit poorly. That is a fix that I am working on. I did pull the underbelly plastic card board down and put bat insulation in there as much as I could. R-30. The front storage below the closet / bed was bare wood. I put 3/4" foam board where I could and used the spray foam insulation over the board and steel frame. That made a huge difference in the bedroom. I have insulated all the access panel in the pass through storage, that cover the furnace and WH. Filled the plumbing holes with spray foam. The hook up doors were thin and not insulated. I put the foam board on them also. Everything helps. I will tackle the cabinets this weekend, as you say the pots are cold and I can feel air coming through the drawers.

[dustman_stx]

The hole size is about construction speed. It's a lot easier and faster to thread pipe through a 2" hole than one that is barely big enough for the pipe to go into. Plus, with tolerances you are much more likely to get an easily accessible and usable entry hole if it is substantially oversized.

[scottg985]

I have been fighting the cold and leaks as most have. I found out that the floor in the neck area was not insulated between the plywood and fiberglass shell. 14 cans of spray foam later, I have that fixed. The application was pretty simple. I pulled the carpet back and drilled 1/4" holes, stuck the straw in the hole and started filling. That has made a big difference in the temp of the floor by the closet.

Next was the rest of the closet. I pulled the corner pieces out and found the bare fiberglass nose cap and air leaking in. I filled that with foam and installed the corner pieces back. With no furnace heat running, only a 1500 watt heater in the closet. I used to see a large temp difference between the heater and nightstand. Heater set on 60 and the thermometer on night stand would be above 70. The closet was so cold, the heater would not cut off, but over heat the rest of the bedroom. Now, I have less than 3 deg diff between them.

I did pull the shelf rack out of the wall and look in the nose area of the 360PDEK. I found insulation in there, but some very large gaps. I will tackle that this weekend. I can say that FR with the front closet is a huge air leak area and will let the cold in. I know that were the cold gets in, the cold will get out too, so this will help in the Texas summer also.

[Thurman]

I recently saw a video (possibly Youtube) that shows an RV owner placing a small fan onto one of his roof-top vents to pressurize the cabin while he looked for leaks. He removed the cover of the vent and using a fan, as is used to dry floors, he fabricated a tunnel from clear plastic/duct tape to direct the air from the fan into the cabin. He then sprayed a water/detergent solution around things such as windows, all sidewall vents, etc. while looking for bubbles and found a lot of air leaks. I thought it was a cool idea.

[scottg985]

https://plus.google.com/photos/10881...47344999575761

[Scootdawg]

Wow there are a lot of leaks, and their Class C doesn't look that old either.

[scottg985]

That was my brothers new class C. Good thing he loves those projects.

[Scootdawg]

Now I need to stock up on some chaulking