New floor and the Toilet

westend wrote:

- The greatest concern would be humidity. Engineered flooring will still shrink and expand somewhat and it's very important to maintain humidity within a certain range. Manufacturers state that it should be kept within 30-50%. Due to the wide humidity level extremes RVs experience from summer to winter, that's not possible (in a house that's easy once it's built and occupied and heating and/or A/C is running). If you travel around the country, you could experience low humidity in one region and high in another. It's also very important to maintain the same humidity level on both sides of the engineered flooring and that's not possible either. The top finish layer can shrink and expand at a different rate than the substrate and some wood species could exacerbate damage from moisture changes. Failure to control the humidity level can result in serious and permanent damage.

You were doing pretty good until you got to the above paragraph. I've installed a lot of square feet of different engineered plank systems. I've installed in basements, in Hawaii (open patio door 1 mile from the beach), and in dozens of other homes where humidity is not controlled like you state. I have never seen a failure due to excessive humidity. As for controlling humidity underneath, that is part of the purpose of an underlayment or a plank that has an attached back. It is usually a caveat for basement installation.

If these engineered planks are installed in a high humidity area, the expanse of the floating floor will expand rather than the plank swelling and losing the veneer layer (in the case of wood veneer plank). The expansion is minute in each plank but many minutes can make up to a 1/4". My own experience is that, if the installation area is a typical residence on above grade level, the laminated planks will not expand even in the gap allowed for such. I have Pergo in part of my house that has not moved 1/32" in 20 years.

Thanks for the feedback everyone! To address the above, the reason for 3/8" in the slide out. I'm pretty sure 5/8 will scratch and snag the slide when it comes in. My current setup is a mixture of carpet and sheet vinyl. It's only the sheet vinyl areas I am looking to cover and the 3/8" brings the floor to the same hight as the carpet. The 5/8" brings it higher so I don't think I have much choice.

Thanks again!

If the differential rises above 20% between indoor RH and humidity level of the floor, that's when damage starts to occur.

I find that doubtful.

I'm with you on the effects of humidity swings like storing a trailer in very humid conditions and possible damage. A lot of these products have a chip fiber core and there is little quality control with some products (who knows what they are using for binders and glue?). Dupont, AFAIK, is the only mfg of laminate flooring that uses a synthetic core. Pergo makes a good encapsulated product. What you get with that is a HPL coating that is built better than your countertop. I also wouldn't be afraid of installing a name brand wood plank in an RV. If it's installed correctly and there isn't any standing/dripping water, there shouldn't be a worry. It's been done.

We didn't put a new floor in the bathroom but we did the rest of the trailer. Got the engineered wood from Lumber Liquidators, (25 Year warranty). Its a floating floor and really looks great. I was wandering how it would hold up so I took a 12 inch piece and put it in the dish washer. Ran it through 12 cycles at home over a couple of weeks. Still looked like brand new after that. So if we spill a few drops on it in the kitchen I am not too worried about it. And the new floor looks great.

westend wrote:

You were doing pretty good until you got to the above paragraph. I've installed a lot of square feet of different engineered plank systems. I've installed in basements, in Hawaii (open patio door 1 mile from the beach), and in dozens of other homes where humidity is not controlled like you state. I have never seen a failure due to excessive humidity. As for controlling humidity underneath, that is part of the purpose of an underlayment or a plank that has an attached back. It is usually a caveat for basement installation.

The manufacturers state that a warranty is void if not maintained between 30-50% or close to that (some CYA to this of course). It's not just the humidity level as I understand it (and if the material is acclimatized before installation), it's the wide swings in humidity and how often and how quickly (as well as the thickness, wood type and/or quality). The flooring also has less chance of damage if it is installed/used in a humidity level close to what it was in the manufacturing plant. I know this flooring gets installed in basements and high humidity areas lots but I think what helps it is that once it's installed, the indoor humidity and temps (ground temp. is quite stable) normally don't change a lot and as much like they would in an RV, and the humidity level of the top and bottom of the flooring isn't that much different. While an entire floating engineered floor will shrink and expand with humidity, because the veneer layer is a different species, it can shrink and expand at a different rate depending on the species and humidity differential resulting in cupping.

The worst case might be in the winter if you're in a cold/dry climate and take your TT out for a camping trip and suddenly generate a lot of moisture inside from cooking, showering and from bodies creating a large humidity differential in the wood which then quickly changes again when you go back home. If the differential rises above 20% between indoor RH and humidity level of the floor, that's when damage starts to occur.

Anyhoo, I couldn't find any opinion from any flooring experts on google for engineered flooring in TTs or feedback from TT owners and everyone basically recommends vinyl laminate over any type of wood flooring product.

- The greatest concern would be humidity. Engineered flooring will still shrink and expand somewhat and it's very important to maintain humidity within a certain range. Manufacturers state that it should be kept within 30-50%. Due to the wide humidity level extremes RVs experience from summer to winter, that's not possible (in a house that's easy once it's built and occupied and heating and/or A/C is running). If you travel around the country, you could experience low humidity in one region and high in another. It's also very important to maintain the same humidity level on both sides of the engineered flooring and that's not possible either. The top finish layer can shrink and expand at a different rate than the substrate and some wood species could exacerbate damage from moisture changes. Failure to control the humidity level can result in serious and permanent damage.

You were doing pretty good until you got to the above paragraph. I've installed a lot of square feet of different engineered plank systems. I've installed in basements, in Hawaii (open patio door 1 mile from the beach), and in dozens of other homes where humidity is not controlled like you state. I have never seen a failure due to excessive humidity. As for controlling humidity underneath, that is part of the purpose of an underlayment or a plank that has an attached back. It is usually a caveat for basement installation.

If these engineered planks are installed in a high humidity area, the expanse of the floating floor will expand rather than the plank swelling and losing the veneer layer (in the case of wood veneer plank). The expansion is minute in each plank but many minutes can make up to a 1/4". My own experience is that, if the installation area is a typical residence on above grade level, the laminated planks will not expand even in the gap allowed for such. I have Pergo in part of my house that has not moved 1/32" in 20 years.

Some points on the engineered flooring that come to mind.

- At 3/8" thick that means it's the lower cost stuff and will have a really thin top veneer layer. More easily damaged and not repairable.

- At 3/8" thick you can or will likely run into thickness problems like under entry door sill, under cabinet doors, drawers, etc.

- At 3/8" thick as opposed to 5/8" or thicker, it will have fewer plies (layers) and will be more susceptible to damage from humidity changes.

- Engineered hardwood flooring is much more easily damaged from dropping things on it, dog's nails, walking around on dirt & grit tracked in from outside, etc.

- The edge abutting a tub or shower could be a problem in keeping moisture out while still allowing the floor to move.

- The greatest concern would be humidity. Engineered flooring will still shrink and expand somewhat and it's very important to maintain humidity within a certain range. Manufacturers state that it should be kept within 30-50%. Due to the wide humidity level extremes RVs experience from summer to winter, that's not possible (in a house that's easy once it's built and occupied and heating and/or A/C is running). If you travel around the country, you could experience low humidity in one region and high in another. It's also very important to maintain the same humidity level on both sides of the engineered flooring and that's not possible either. The top finish layer can shrink and expand at a different rate than the substrate and some wood species could exacerbate damage from moisture changes. Failure to control the humidity level can result in serious and permanent damage.

- You should make the flooring fully floating by using the interlocking type of engineered hardwood and not glue it down to the subfloor or glue the joints together.

Interlocking vinyl plank laminate avoids the pitfalls of engineered hardwood and is the way to go in a TT for a retrofit...

You're mixing up a few terms, there. Most TT's come from the mfg. with either vinyl sheet flooring or carpet. The vinyl sheet can be overlaid with engineered wood plank, a composite of wood veneer glued to a substrate of various wood products or vinyl laminated plank, a composite of compressed wood fiber with a vinyl wear layer on the finished surface. This can resemble wood grain and can even be embossed to represent wood surface imperfections. Either of these flooring products can also have a foam layer on the bottom which can eliminate the need for an underlayment material to be installed underneath the plank. There is also available complete vinyl plank (Allure, Dimensions, etc.) which is made totally of vinyl.

I'm of the same mind, as to water on the surface, I can actually take a shower or use the sink without a gallon of water dripped on the floor. Some folks are challenged by this, I assume.

When I installed vinyl laminate in my trailer, it came with foam backing but I chose to also install a tough underlayment. The price was not that much greater and I thought that the underlayment would keep moisture from reaching the plank from below and allow a better feel under foot. Results have been good.

myredracer wrote:
Vinyl laminate planks with simulated hardwood look? Surely not engineered hardwood or real hardwood? Any kind of standard or engineered hardwood is not a good idea. Shouldn't be any type of glue-down product either. Vinyl laminate is quite thin, about 1/8" and is pretty much what everyone is using in their RV.

So on the basis of using vinyl laminate planks:

The toilets use a foam seal/gasket and not the wax one in a house. The toilet flange is like the one in a house. The foam can't tolerate much of a floor thickness change, unlike a wax gasket, but 1/8" may be fine. You want to make darn sure the gasket never leaks. I did laminate planks in a previous TT that was about 1/8" thick and the foam seal was fine. Make sure you use a new foam gasket and not the old one. If things don't look right, you could use a toilet flange extender (made from plastic), which are around 3/8" or so thick, but probably too thick. Many have successfully used a standard wax ring, but if it gets too warm inside, the wax could soften too much. Wax rings come in a thicker "extender" version if needed. I don't know if two foam seals would be a good idea, but some have done this.

There's always a chance that your flange is threaded into the black tank. If so, you can unscrew the flange enough to make up the difference in floor thickness. Cut some pieces of the flooring and put under the flange as a spacer and re-install the screws. These pieces should not extend beyond the flange (to allow for the expansion gap).

You don't want to install the flooring and have a gap around the base of the toilet as it will look awful, plus you can't fill the gap with caulk as the flooring needs to be able to move.

You want to lay the laminate down close to the toilet flange. Make an expansion gap all around of 1/4 - 3/8" so that the laminate is free floating. The laminate needs to be free floating everywhere inside the TT with an expansion gap around the perimeter and where there are penetrations like floor vents, toilet, etc.

Good luck and post pics of the finished project.

Thanks, this is great info! Why not engineered wood? I believe that is the plan as I have seen many people use engineered 3/8" engineered hardwood (or maybe it is laminate wood looking planks??) as a floating floor on top of the existing laminate floor. I actually got to see my exact model with this done and it looked great. I understand the fear of water expanding the wood but we use a large bath mat next to the shower and maybe only a drip or 2 actually gets on the wood. Very similar to our 1/2 bath at home which is hardwood. Please let me know your thoughts and thanks again!

Yes, you'll either have to raise the flange or contrive a gasket that is thicker than the original. What I did was make a square 1 1/2" H riser box and installed a new flange with longer drain pipe. That made it easier to install the laminate planks and raised the toilet 1 1/2".

Vinyl laminate planks with simulated hardwood look? Surely not engineered hardwood or real hardwood? Any kind of standard or engineered hardwood is not a good idea. Shouldn't be any type of glue-down product either. Vinyl laminate is quite thin, about 1/8" and is pretty much what everyone is using in their RV.

So on the basis of using vinyl laminate planks:

The toilets use a foam seal/gasket and not the wax one in a house. The toilet flange is like the one in a house. The foam can't tolerate much of a floor thickness change, unlike a wax gasket, but 1/8" may be fine. You want to make darn sure the gasket never leaks. I did laminate planks in a previous TT that was about 1/8" thick and the foam seal was fine. Make sure you use a new foam gasket and not the old one. If things don't look right, you could use a toilet flange extender (made from plastic), which are around 3/8" or so thick, but probably too thick. Many have successfully used a standard wax ring, but if it gets too warm inside, the wax could soften too much. Wax rings come in a thicker "extender" version if needed. I don't know if two foam seals would be a good idea, but some have done this.

There's always a chance that your flange is threaded into the black tank. If so, you can unscrew the flange enough to make up the difference in floor thickness. Cut some pieces of the flooring and put under the flange as a spacer and re-install the screws. These pieces should not extend beyond the flange (to allow for the expansion gap).

You don't want to install the flooring and have a gap around the base of the toilet as it will look awful, plus you can't fill the gap with caulk as the flooring needs to be able to move.

You want to lay the laminate down close to the toilet flange. Make an expansion gap all around of 1/4 - 3/8" so that the laminate is free floating. The laminate needs to be free floating everywhere inside the TT with an expansion gap around the perimeter and where there are penetrations like floor vents, toilet, etc.

Good luck and post pics of the finished project.