Steam Room Construction Tips

What insulation type (and what value) is recommended inside the walss of a steam room?

fiberglass R-13

What about the light fixtures? My contractor is using regular "can lights" with a trim piece/lens that has an extra gasket that he says is rated for wet locations. It's not that tight and the lens has some wiggle-room too. I'm concerned about moisture getting up into the above floor joists.

Mark,
You should be concerned. Think about using lights that you find in swimming pools.

I'm looking at using a man-made stone material for the shower base, walls, and ceiling. Would the product "denshield" work as the substrate? I'm guessing that the one piece membrane would still be needed, and all corners, seams, and panels would be sealed and attached with silicone caulk.

Craig,
I would not use that. In a steam bath, I would only use pure cement board.

I installed a steam shower last year with good ventilation; yet I have had repeated problems with the grout at the seam between the inside wall and floor seperating. Is this because of the high temperature and humidity levels and do I need a special grout? I was using the standard DAP latext (not silicone) Kitchen and Bath tile grout.

Please advise,

Jan

Jan,
Are you talking about grout or *caulk*?

Sorry, I meant the caulking.

Thanks,

Jan

Jan,
You need a urethane caulk approved for use in showers.

Thanks very much, With this I will use a silicone, as opposed to a latext based caulk.

All the best,

Jan

Jan,
No. You need a *urethane* caulk. Please read my past columns about these wonderful products.

Can you use a product similar to pro-flex in lieu of the vapor barrier and if you can should I install it over the cement board (Hardie backer board) and then tile over the proflex? Od does the Proflex have to be installed before the cement board?

Walter,
I would use a product that had the lowest perm rating. Go read my past columns about high-performance vapor barriers.

We are about to renovate a steam room w/ actual room size of 2.65x4.47M and we were advised to provide exhaust vents below the benches to reduce "latent heat".Is this advisable?Becoz there's an existing exhaust vent already on the ceiling.Thanks...

Bong,
I have never heard of that..... and have never done it in the steam rooms I have successfully built.

Is a ventilation fan inside the steam shower room advised, or required?

Thanks

Doug.
No. The air you bring in will eat the steam.

I'm sorry, I didn't mean using it to bring air in, but to ventilate the steam/ air out - after one is finished using the steam shower - similar to a typical ventilation fan in a bathroom. Thanks

Doug,

That is a good idea.....

Great. Do you know of/ recommend any vent fan that won't be affected by the steam? Like a sealed-type unit?

Doug,
I thought you just said there would be no steam........ Please read all of my Bath Ventilation Fan columns and look at the unit with the shiny flexible insulated ducts.....

I assume the vapour barrier is affixed directly to the wood frame walls and ceiling. How do you affix the poly without puncturing it?

Also, how do you use cement board inside the poly as a substrate for the tiles without puncturing the poly?

tx

Second Craig,
The fasteners seal the puncture. The vapor barrier is under the cement board.

When you attach the cement board over the waterproof membrane, do you nail it? Won't this put holes in the membrane, or is it self sealing?

Thanks RP

Robert,
Self-sealing......

I have just replaced an existing steam room because it was condesating on the backside of the backerboard and causing water to form. We stripped it down to bare studs, reframed the ceiling to the correct pitch. Install 6 mill plastc, Hardi Board, coated this with Mapei Mapelastic (PRP 315)troweled on waterproof membrane. We then installed the tile using Mapei's Kerabond Thinset modified with 100% Keralastic acrylic additive. We grouted with Mapei's Kerapoxy 100% solids epoxy grout. Guess what? We are still getting condesation built up between the plastic and the Hardi Board. Any suggestions?

Thomas,
That is normal. What I have done on all recent installations is to create a 1/4-inch airspace between the vapor barrier and the backerboard using ripped treated-lumber strips. The vapor barrier laps over the shower flange or into the CPE shower-pan liner so the condensate is taken to the floor drain. It is IMPERATIVE that you use the high-quality vapor barriers I mention in my Vapor-Barrier columns. You should not use regular poly.

there are several waterproofing materials that can be brushed,rolled,or sprayed on the cement board directly, as pro-red,or several other comparable products? is this type of waterproof membrane adequate for steamshower use, and if it is recommended/o.k., then would you still use a poly layer under the durock?

Randy,
I have not used those. There is no substitute, in my opinion, than a one-piece high-quality vapor barrier under the cement board.

I am building a steam shower that is 5 x 6 and was planning to make the front all glass, how will the glass effect the performance of the steam shower? or should I reduce the glass and if so how much

Rick,
The glass will not make any difference.

Are you familiar with the Wedi products? And, if so, would you recommend their wallboard materials in a steam shower app?

Teague

Teague,
Never heard of them.

Hi Tim,

I am designing a steam room about 3ftx5ftx7ft(high). I have access to natural marble in slabs or tiles. I would prefer the slabs because they will reduce the number of grout joints but the slabs only come in 3/4" (2cm) thickness. I am concerned that the 3/4" material with cement board behind it may act as too large a heat drain and my steam might just condense on the sides. Is this a warranted concern?

If I go with tile, am I better off going with very large tile (24"x24") or is small tile on mesh ok... again, I'm concerned about grout a)allowing moisture to transfer through the wall and b) creating rough surfaces for mold to grow.

Thanks for your comments

Tim,

Are you familiar with fantech's being tested for use in steam showers? Would you recommend one of these units to be installed in the ceiling of a steam shower for venting of steam after a steam bath? They have a spring loaded baffle in them but I would think that steam would still escape even with the fan off. Any thoughts on this?

Thanks

Please indicate which materials you prefer for steam room walls and ceiling:

Cermamic tile, natural stone tile, solid surface material (sheets)

thanks

Ed,
The large slabs of marble will not be an issue. Think about the steam rooms in the old YMCAs across the USA. They were thicker tile set in thick mud beds! Go with the marble. It will be stunning. I would be honored to put photos of it on my website giving you full credit!

Teague,
What did you learn from Fantech?

Ed,
Tile or granite.

Tim,

as far as my Fantech fan research goes...I have been working with steamsaunabath's tech line and have been made aware that they are currently working with Fantech to develop a sealed-duct unit that can be used successfully in a steam enclosure. At this point I know they are testing a regular Fantech model and checking the temperature loss through the spring-baffle and duct. It makes sense to me to have some form of steam evacuation on the interior of these in-home steam showers. I will try and keep you updated.

I have a steam shower that our builder put in and We put in synthitc marble. It keeps buckeling and letting lose. Should we have chosen tile instead? What are your suggestions.

does the door have to be completely sealed for a steam shower?

We only installed the vapor barrier half way up. No vapor barrier is on the ceiling. Instead of using the steam, can we just use it as a regular shower? Or do we still have to remove the tiles and start from scratch.

I have read different articles about constructing a steam shower, and I still have a few questions.

I am installing a shower door with a hinged transom to allow some ventilation in the room after the shower or steam bath. Should I still install a vent fan for after the steam bath to reduce mildew, or is this overkill?

I have experienced ceilings dropping water on me while I sit in the steam bath. What is the correct pitch for the ceiling of a steam bath/shower enclosure?

Brandye,
I would have selected tile or granite installed on cement board with thinset.

Jason,
The door doesn't need to be perfectly sealed.

Roberta,
If the entire steam shower is inside and not near an exterior wall you May be okay. If there is insulation directly above the shower, monitor it for moisture in the winter.

What a great resource...
I intend to build a steamroom outside in an alcove using one wall of the house because it has ready access to 240V and water and roof overhang.
1) The dimensions will be 3ft x 5ft x 7 ft with a 2" per foot decline in the ceiling.
2) The steamroom will sit upon existing poured concrete that has a slight pitch outward. Weep holes will be utilized.
3) My exterior wall that will be used is stucco. I will cover that with one piece of Marble slab and mount a fold down bench.
4) The door will be 3/8" glass 26" x 71" with tiled pillars either side for the doorway enclosure and mounting. This will be wall #2.
5) The two remaining sides (5' and 3') will be 3/8" glass at a 90 degree angle to complete the rectangle.
6) I am undecided as the height of the two exterior glass walls.

Q1 - for the ceiling, can I use cement board and caulk the joints?
Q2 - Must I use a vapor barrier on the backside of the of cement board before mounting cement board....or is the thinset adequate?
Q3 - Must I seal the facing side of the cement board before applying thinset and ceramic tile?

I appreciate your time.
NB

Bob,
You need to read this column:

http://www.askthebuilder.com/717_Steam_Room.shtml

I am installing ceramic tile on a block wall constructed steam room with a concrete floor. How should the walls and floor be preped and will a fortified thin set morter work well for this.
Thank You,
Jeff

Jeff,
I would read all of my Steam Room columns, there are several, and I would read all of my Ceramic Tile columns. The answers you need and much more are there.

If you are looking for a true water proof/steam proof barrier that is designed to be applied right over sheetrock, take a look at Schluter's "Kerdi" product. It's a fleece lined polyethylene sheet that is held in place with thinset. When overlapped 2" it's 100% waterproof. I researched steam room construction for over a year and found this is the easiest solution.
-Mike

installing a steam shower. does the ventilation fan go inside the shower or out? how thick should the barrier vinyl be? can you use glass tile? would you use seamless european doors? thanks. Lisa

Lisa,
Outside. 6 mils. Yes. Yes

would it be ok to mud the walls instead of cement board? and would redguard work as a barrier?

Aaron,
You can mud the walls. Look to see if that product has the ASTM E 1745 certification.

I am in the process of consructing a steam shower. I have been on several sites and read the threads, however I do not see anything related to using Granite on the walls and lid. Does anyone have any feedback on using Granite?

Karen,
Granite will perform well in a steam room. Make sure you seal it well, and squeegee it down after getting out of the steam room.

I have installed a steam room. We are experiencing condensation on the two walls common to the exterior. The two walls common to the interior, no condensation. We do not have a polyethelene vapor barrier as suggested here. What we do have is glazed ceramic tile at walls and ceiling over 1/2" hardibacker which was treated with a paintable membrane like "Redguard" at the walls and ceiling. Sloped ceiling. We also used a specific grout with an additive recommeded by the grout manufacture for this purpose. Our steam generator is located behind / below our steam room bench. This area gets pretty warm and we have a lot of condensation at the interior face of the exterior sheathing in this area. Looking further we have found condensation on the exterior sheathing at all of our exterior wall sheathing. These wall cavities are insulated with non faced R-21 fiberglass batt insulation. Initially we thought this was due to heat passing by the insulation along the stud and then condensing on the cold sheathing. Now I'm not so sure. What do you think?

What do you think about using "liquid rubber" (Sani-Tred, etc.) as vapor barrier?

I have an outside wall that has a built in glass window (square tile kind). Should I take this out and redo with concrete board or is there a way to keep the outside light while keeping moisture from escaping?

Thanks so much and take care,
Kirk

Tim,
I feel like I have researched forever and can't seem to find any recommendations on a prefabricated steam shower unit. As a result I will probably do a custom build instead but if there is a product you would recommend or specifications for shopping for a prefab unit I would appreciate it. My space is 5x5', budget $4000 total.

Thanks so much!
Kris

How good or reliable is a vapor barrier that has been nailed and the barrier has been punched? In a steam room application where the vapor is pressurized as stated on the site. Wouldn't these holes present a problem?

Hello, I am converting an existing shower. 9'H X 6.5'L X 3.5'W. The walls will be glass mosaic, epoxy grout, with 1/2 thick glass door entrance spanning floor to ceiling. After tearing out tile and drywall, I plan to use a proper vapor barrier. In addition, I understand the ceiling should slope. What is a good steam generator to purchase, and how much should I slope the ceiling? Are there any good steam generators which run off 120V? Thank you so much for your advice.

is using the same vinyl product from your pan good enough for walls and ceilings? also crossing 1/4" hardi board over 1/2" hardi board with thinset in between reasonable to do?
thanks
Don

How do you treat the polyethylene barrier around the doorway? At what point on your way out of the steam room can you end the barrier and how should it be sealed?

Is this vapor barrier critical? Can cement board, along with sealing the seams with additional cement "mud", work fine?

Also, what type of ventilation fan should I install? Something over 130cfm's or is that not as critical as long as it's truly vented outside?

What is the best type of grout for a steam room? We used Quartzlock and after using the steamer the grout seems to soften and wants to fall out. Any ideas?

Hi

I plant on covering the walls and ceiling with 15 MM thick tempered colored glass. There is going to be one piece for each wall and one piece for the ceiling. What do you recommend for wall boards and a barrier?

Thanks

CAN MARBLE TILE BE USED IN A STEAM SHOWER?

I'm interested in building a steamroom/shower with two shower heads and two benches in a first floor master suite on a outside wall corner. I would like one glass wall with a gasket sealed door for access. I think I will need to have ventilation both for the steamroom/shower combo room and the room into which it opens. Is there any guideline to how much air needs to be moved? I'm thinking an adjustable fan unit with either separate vents of two vent intakes gathering to a single exhaust.

can we use wood for the sitting area in the steam room

I want to add a bathroom that includes a steam shower. My house is 27 years old and my 200 amp box is full, therefore, I decided natural gas would be my solution for the steam generator, but to my surprise I can not find one. Could you please help with any info?

I am finding it differcult to find info, like the steam unit it self how big is it, what area does it require, what sort of ventilation is required to a steam room, this is for a wellington, nz site.

Thanks for your great column. Do any of your past articles answer these three questions: 1) how far down over the floor pan is the vapor barrier draped? 2) What is the best (from a value standpoint)steam unit? 3)is there a good source for determining the cost of running a steam room?

I am currently building a home and want to make sure my sub contractor is doing my steam shower install correctly. I know this is a dumb question but are you suggesting the vapor barrier be placed under the cement board or over the cement board but under the natural stone walls and ceiling? Thank you in advance for your help.

is the vapor barrier beneath or above the durock cement board. only one piece?
thanks ,
frank

we are putting in an 6 x 12 double shower with a steam unit using porcelin tiles except for the ceiling/lid I choose glass tiles and my tile guy is concerned....what do you think will it work or should it take it back and get tile,marble,etc.....

How do you properly ventilate a steam room (for excess steam/pressure) if you had a tight-fitting door?

Could you let me know what ventilation and where to fit. The steam room is in a cubicle. It is sealed at the moment but i understand will need ventilation. size is aprox 3 cubic meters.

I am amazed at your suggestion about the use of cpe membrane for walls and ceiling instead of a "Red Guard" membrane which is brushed on the cement board or a simular Hydroguard product. Much easier and effective less difficult than folding corners and second person.

I'm planning to install a shower/steam room and want one side to be glass from top to bottom with a window. Would you know if that would have an effect on its functioning? Is there a certain type of glass that would work best?

Can you use porcelain tiles in a steam room?

I see you said to create a 1/4" air space between vapor barrier and backerboard using ripped treated lumber strips (I'm using Durrock). Does Durrock need to be taped before I tile? If so, what kind of tape and mud do you recommend?

Should I use block masonry or conventional construction? With conventional, I assume 2X4 walls on 24 centers. What about the ceiling? Also 2X4 on 24's? R13 insulation and what about the floor barrier? If I put stone on the floor, where do I run the barrier?

Using the vapor barrier you mentioned for steam spas, my concern would be nailing the barrier to attach it to walls and ceilings. Wouldn't this allow moisture to penetrate the barrier?

Hi
I have a steam room that is ready for tile and was wondering what you suggest is the best tile to use..i.e., ceramic, porcelin etc ?
what about granite for the bench ?
Thanks
Garry

When building a seat for a steam room, what product, metal framing or treated lumber would you recommend?

I am thinking of using limestone or another natural stone in a residential steambath. The advice I have gotten is mixed about whether or not that is a good idea. Some suggest only porcelain, others think that marble, or limestone, sealed once a year will be fine. What has been your experience? Thanks for your help.

I've been looking at the Helo steam generator website but this says that no special grout is needed for steam, nor are special lights needed.
Regarding your advice in the article on sealing a steam room, once the plastic vapour barrier is installed, how can I stick tiles onto a plastic sheet?
How can the plastic sheet come inside the shower tray if the walls are tiled?

Are there any issues in using Corian for the walls of a steam shower?

Thanks

You recommend a one piece cross laminated virgin polyethylene sheet. Can two sheets be used if the manufacturer recommended 4" vaporblock tape is used to seal the seams?

I am looking at the RUFCO 300 products from Raven Industries.

I have a similar problem where the ceramic walls meet the floor of my steam room. There is a gap all the way around and I am wondering what is the best way to correct this problem. Do I use a urethane caulk approved for use in showers or apply more grout to seal the gap? If you recommend grout...what kind?

Thanks!

Hi Tim, I've read your columns on steamroom construction and I plan on using a manmade product (such as Swanstone or similar) for base, walls and ceiling. Am I correct that a cement backerboard needs to be used in this application? What thickness backerboard do you recommend? And what adhesive do you recommend using to attach the material to the substrate?

Thanks. I use your site often. Lot's of good info.

Will a ceiling assembly of waterproof membrane, cement board trowled with a layer of plaster hold up in a residential steam room application?
the steam machine will be used a few times a week. The walls and floor are corian.-Thx

Jan,

I want to build a outdoor steam room next to our hot and cold tub.
I am thinking of just making using 2X8 redwood as for my walls and nothing more. It would be off the ground with a partial glass door adjustable air vent for intake and exhaust air. Do you see this to be workable and if so any precautions.
Winter's will go into the -20's.
Thanks, Harold

I am going to build a commercial steam room. I have been looking around on line for information. Do the walls need to be tile or can I use some fiberglass?

What about having limestone on floor and walls of the steam? what other natural stone is recomended for the steam inside? I want to give it a spa like feeling.

Installing a steam room in my house. Do you install the vapor barrier behind the durorock to the studs, or on the inside where the tile gets attached?

do we need to install any type of ventilation system as in exhaust fan or what do you recommend?

what would you recommend for ventilation of the steam room?

I am interested in a steam shower installed. One of those prefabricated units. My problem is that the hight of the washroom in the basement is only 6 feet. Are there any steam showers with 6 feet hight?

what do you do with the vapor barrier on the ceiling if you have rain heads, can lights etc.??

I have one quick question regarding steam room ventilation. I have a Building Department Correction from a third party outsource plan reviewer who has requested the addition of a ventilation fan within the steam room enclosure. The enclosure is within a covered outdoor structure with one wall completely open to the outdoors, but that is outside of the enclosure. The plan review states per 2007 CMC Section 403.7. a ventilation fan is required within the steam room enclosure. Is this correct?
Thank you,
John
California
(2007 CBC, 2007 CMC)

Looking to build a steam shower but not sure on what type of material to use. Contractor suggested that I not use travertine stone because the steam will penetrate and may develpe wtaer problems. He suggested I use porcelain. Is that accurate or can I use travertine stone, (Preferably stack stone).

Hi there,
am having to retile the benches in our steam room - the originals appear to be some form of non waterproof board which ultimatley failed through moisture ingress. We will be keeping the same structure, but will be recovering both seated area and back of benches before retiling. Any thoughts on best product to use to be stable and water proof. Doug. Scotland

We are constructing a 550 cubic foot steam room. The room has a separate exhaust 250 CFM exhaust fan with a spring loaded damper in the center of the ceiling. The glass entry door closes tight making the room fairly air tight. In order for the exhaust fan to work properly, do we need a make-up air duct near the bottom of one of the walls? If so, could a standard heating wall boot be used with insulated hose/duct connected to a roof jack? Thanks!

hi , i am building a steam room for a client i have built lots of shower enclosures but not a sealed steam room, i understand using a vapor barier but do i have to water proof the cement board before putting the thinset and tile on it or should i use a special thinset for the higher teperatures??

Although the tilers for our steam room have put a large black liner under the cenent floor, they have rolled a product they called 'red guard' onto the walls and ceiling. I haven't seen any comments as to this on your site. Is it alright?
Sandra

in my steam room .. i had a green board ceiling..
how could i tile a false ceiling then?
should i use a cement board below tiles? or replace it with an another kind of ceiling finishings..like a corregated sheet panel..etc..
p.s : it is a gym..and it will be used at least 12 hrs daily.
the const. system used is concrete so no problem in loads.