found soft spot in floor

westend wrote:

isonychia wrote:

westend wrote:
It sounds like leak prevention has been an afterthought. I'd suggest to do an interior pressurized leak test. That will reveal any structural leaking. You can check plumbing supplies and drains by operating them. Check tightness of plastic drains while you're there.

An afterthought? Not really.

An uneducated rv person, yes.

I assume the pressurized leak test is for the plumbing system?

I have been on the roof a few times and visually inspected all the lap sealant etc. I have never noticed any problems. However, if subtle pinholes can let in that much water, than that is something I cant prevent. In which case people should not bother inspecting all the seams on a TT roof and just keep putting on loads of lap sealant every year.

Everytime I look at these seams it's impossible to tell if there are any pinholes. Between the bumpy texture of the lap sealant and dirt that covers things, pinholes can easily get unnoticed. Even after cleaning the seams it's tough to tell.

The system these companies use to build these things is horrible.
These TT have flat roofs, with a rubber membrane and there are 10 items penetrating the roof, antennae's, vents, AC units, solar panels, ladders etc etc. It's just a combination for a disaster.

To make matters worse, they use luan roof panels, OSB subfloors and wood framing.

I understand it's the nature of things, it's just a little annoying to try and prevent leaks when the system is not designed well.

I take all the precautions I know how. I cant prevent them all if I cant see the problems. I visually inspect the inside of the trailer and always feel the walls and floors for any signs of wetness or softness. Thats how I found out the water heater drain plug flange lets water in from the outside.

If pipes running underneath the subfloor have sprung a small leak and are wetting the subfloor, thats impossible to find. It's hidden.

The AC thing is definitely my fault. After some researching I didn't know they were a major source of water problems. I didn't know I was supposed to tighten the bolts to make sure they have not come loose. (I don't move the trailer, it's static)
I didn't know I need to dismantle it, remove it from the roof and check the seal to see if it needs to be replaced. Now I do.

iso

The pressure test introduces a large volume of air into the interior of the structure (accomplished with various blowers) and a soap solution is sprayed onto the exterior, including the roof. Any pinhole or void will bubble up readily.



I understand your opinions on the membrane roofs. IMO, they aren't a good solution to a transported house. They do require continued maintenance unless......you discover Eternabond tapes. The tapes are time consuming to install because the surface needs to be immacuately clean (think solvent clean) but, after installation, they guarantee a leak-less seam. There are many on this Forum that advocate for Dicor lap sealant, preferring to add some over existing seam sealant. They report no leaks so both systems have adherents.

The AC seal is what it is. If the gasket is observable to be intact and your confience is up, you could try tightening the bolts. I'd opt to remove the bolts, pull the AC and install a new gasket. Age does have her ways.

Getting back to the flooring issue: A composite panel floor made from a sandwich of plywood sheathing and foam is a disaster waiting to happen. The interior plywood sheathing is not rated for floor use so any loosening of the foam to the plywood skin results in a failure of the panel. These composite panels are good for walls and roof applications but fail as floor systems. The repair is to remove interior faced plywood and flooring, exposing the foam (or what remains of it intact), installing a filler that will adhere to the new plywood floor sheathing replacement (typically spray foam). Install new flooring.

If you're blessed with a conventional floor rated floor sheathing attached to floor joists, repair is much easier. Flooring is removed, plywood is examined for failure and replaced as needed. Any damage to floor joists from water leakage or rot can be replaced or ledgered from the interior.

FWIW, after I removed the carpet inside my trailer, I ended up cutting the plywood sheathing out to both repair rot damage in two areas and to install foam board in the empty joist cavities.
The under belly of my trailer is a continuous aluminum skin, it provides excellent water shedding.

If you have an assumed plumbing leak or need to inspect the floor from beneath the trailer, both Coroplast or spun fabric can be removed and reinstalled. A search of the Forum should turn up a lot of hits and tips.

Again, I'd suggest to pressurize the interior to locate any or all leaks. Some guys do it with a leaf blower. I use a conventional furnace blower that I mount on a ladder and blow through a removable sash opening in a vinyl window. If this Forum was more friendly about "stickying" instructions for some of these maintenance procedures, I'd capture the process and submit it. I just got tired of listing the whole process. Maybe a search will find one of those threads.

Good luck on finding the leaks and repairs. You're not alone with this. ;)

Thanks for the info westend.

I already ordered 3 rolls of the tape and a new ac seal. I hope it's the 14x14 one.

To clarify. If my floor is composite, foam sandwiched between 2 sheets of plywood, is that simply sitting on top of the floor joists with the lower layer of plywood fastened to the floor joists?

I think my trailer is simply OSB with regular fiberglass insulation. One of the exterior hatches has a seal problem and water has gotten inside. When I was trying to fix it, (adding thicker foam weather stripping) I pulled back the carpeting and I could see the subfloor was simply OSB with fiberglass insulation underneath. So I assume thats how the rest of the floor is.

I also assume R13 insulation is what I should purchase to replace the existing?

A few more questions.
When I remove the sections of flooring how bad is it if I leave the sections under the refrigerator and kitchen sink if there is deterioration on those panels. Assuming I find the source of the leak and stop it?

There is a wall for the bathroom. I am not sure if I will be able to remove the plywood subfloor from under those wall sill plates. I figured I would cut around it if I need to. Is that ok?

Thanks,
iso