Designing Kitchens and Bathrooms - install drywall around a fiberglass shower?

when you install a fiberglass shower do you drywall up to the mounting flange and then mud over the flange? or do you drywall over the flange? thanks for all your help!!
todd durham

todddurham,

Correction was made - read latest posting.

when you install a fiberglass shower do you drywall up to the mounting flange and then mud over the flange? or do you drywall over the flange? thanks for all your help!!
todd durham

You can drywall over the flange, but it will cause a bulge unless you furr out the wall to make the framing flush with the flange. The alternative is to get some thinner drywall or backerboard to put over the flange. Putting mud directly on the flange will not work because it will eventually crack off because the fibreglass is not a good surface to adhere mud to. You need to caulk at the juncture between the tub and the drywall.

todddurham,

Correction was made - read latest posting.

Hi Doug,

You are correct about this for a "base" unit. However, I think Todd is talking about a full stall fibreglass shower unit. While the condition is similar, it has one very important difference. The tub or base unit for a shower are in wet areas and usually those flanges get covered with ceramic tile (in fact drywall shouldn't even be used in those locations) and the backerboard can be stopped short as indicated with the tile applied over the top of both the backerboard and the nailing flange. However, it is still best to furr the wall and install the backerboard over the flange because this provides a better substrate for the tile which is then sealed with silicon caulk to the tub.

In the case of a full shower unit, the nailing flange is outside of the shower wet area and often is covered by drywall. The suggestions I made will prevent the "bow out" in that type of installation.

Sorry, but I've been the Architect on a lot of residential and hospital projects and have always had the walls furred flush with the flanges when prefab fibreglass showers are installed. IMO, the method described in the link you posted is just wrong. Besides, you are quoting yourself :rolleyes:

Joe,

I stand corrected although I would have preferred a better way of saying that.

todddurham,

Please disregard what I have mentioned and look at page 9 of this PDF. This would be considered typical and displays exactly what Joe mentioned.

http://www.us.kohler.com/onlinecatalog/pdf/1030528_2.pdf

Joe, from one professional to another, Thanks.

thanks for all your help guy but i have one more question.......in the case of removeing a old shower and installing a new one should i cut the wall a foot or so above the shower then fir the wall 1/4 inch and install a 1/4 inch drywall over the flange if the wall already has 1/2 inch drywall on it

I assume you have already removed the old shower and found that the wall has 1/2" drywall. If so, I would go ahead and remove the drywall all the way to the ceiling and then furr the studs the thickness of the shower nailing flange and install 1/2" drywall on the wall. There shouldn't be that much wall to redo, and it is usually easier to do the whole wall rather than patch a small area.

ok thats what i will do. thank you guys for all your help.
todd durham

I have a question with regards to the alcove area above the fiberglass shower. What material can be used since drywall is not appropriate. I am hearing that gypsum would work. Is that true, all I want to do is paint the alcove area with appropriate primer/paint. I am not interested in laying down ceramic. Any thoughts would be appreciated.

I have a question with regards to the alcove area above the fiberglass shower. What material can be used since drywall is not appropriate. I am hearing that gypsum would work. Is that true, all I want to do is paint the alcove area with appropriate primer/paint. I am not interested in laying down ceramic. Any thoughts would be appreciated.

There's nothing wrong with using drywall here but you need to make sure the area is well ventilated and doesn't get real wet. Typically you seal and paint this with a semi-gloss paint and caulk at the jucture between the shower wall and the drywall.

Drywall is also called Gypsum Board - that's what it is. Unfortunately, Gypsum is a material that soaks up water like a sponge. That's why it has to be well sealed. There used to be a "green" version of drywall that was more resistant to moisture. I'm not sure if it's still available - if so, use it.

Another option would be a couple of layers of hardibacker. However, you would still be using joint tape and compound plus texture which are water sensitive.

A good primer, semi-gloss paint and silicon caulking are the only real solution if you don't want to use ceramic tile.

Joe, just FYI, greenboard is still available and would be the preferred covering for paint. Use durock or hardibacker if you'll be using tile for these areas.
You can use standard drywall everywhere else in the bathroom. Basically, any area that isn't likely to have water splashed on it.

Remember to use the mud/tape made for greenboard, it is more water resistant than standard mud/tape.

I have a stupid question which is in reference to the same subject matter. When mounting the 1/2" drywall over the flange there will be a gap between the drywall and front of wall of approximately 5/8". Is that normal or should the drywall be flush with the face of the fiberglass wall. I'm thinking the 5/8" would be utilized if mounting ceramic tile which I am not. Thanks

todddurham,

in all the years we have installed showers we have never furred out the wall due to the exact condition you just mentioned. the green board is to be used in all wet areas per code. Second it is up 72" and is above the shower head so you are talking moisture rather than water.

You need to run flat blocking alll around all sides and top of the shower. You screw (predrill first) the lip only to the blocking at 18"-24" o.c. You then install the gyp board keeping the screws up out of the flange so as not to crack the shower. There is only 1/16" to maybe an 1/8' of thickness in the lip. This will cause a minor curl. You caulk the gyp board to the shower and then when you mud you have to mud the curl out the assymbly. When done properly most of the difference is not even noticable.

I hope this helps.

Brian Garrison
General Contractor/Professional Building Designer

Where do we find 1/8" furring (table saw?) and what is it made of? Wood seems like it would disintigrate as soon as you screw it. Any flexible plastic products out there?