View Full Version : laying tile floor - what is proper subfloor?

01-15-2005, 04:49 AM
greetings folks,

best new year's wishes to you all ...

i'm going to lay a tile floor in the bathroom. it's about 10' x 10'.

the original subfloor is rough-cut 1" x 6" plank (so it's true 1"). i've pulled up the various years-worth of decaying add-on subfloors (lauan, ply, vinyl, etc) so the rough-cut plank is all that's left.

some of the boards are slightly cupped, but the floor is quite level overall.

what are your suggestions for the best foundation for ceramic tile, in addition to the solid subfloor there now?

many thanks,


01-15-2005, 03:39 PM
Ceramic tile should have 1" minimum substrate. A good base would be to put down " Hardibacker using screws on every "dot" and thinset mortar underneath. Use an isolation membrane on tob of the Hardi.

01-15-2005, 04:07 PM
I've spent a bunch of time reading at www.johnbridge.com which is pretty much dedicated to tiling. They've got a structural engineer over there that can help. Double check, but from what I've read there, on top of plain lumber subfloor, before tile, they want a minimum of 3/8" plywood (exterior grade with no "D" sides, ac, ab, or bc). The subfloor is only part of the equation - you need to know what the joist size and maximum unsupported span is. Also, are you considering ceramic or stone tile? A stone tile needs twice the stiffness of ceramic. Check it out.

01-16-2005, 03:53 AM
thanks for the input ... now that i'm visiting the john bridge tile website, i'll learn the language - an isolation membrane doesn't sound desirable in my current vacabulary, but i'm sure it IS for tiling purposes!

i think i'll be using very simple mosaic tiles backed with netting for this particular bathroom.

this is a small job within a rather huge building project and i hope to accomplish it fairly quickly (for me, anyway) so i can move into the house and have one partially completed bathroom to use.

it would seem that mosiac tile is one of the easier bathroom applications.

i'm also considering pergo (thanks also for your great laminate-in-bathrooms considerations in an earlier thread) but don't know if installing pergo with glue is more challenging than mosaic tiling for a fledgling installer.

any thoughts on that one?

thanks again - kavita

01-16-2005, 09:47 AM
Most of the Pergo and other brands of laminate flooring today use a snap together rather than a glue joint. They aslo are rated by their manufacturers for use in bathrooms. Most of us have seen much too much water on a bathroom floor sooner or later from leaks, overflows,or even just normal usage to be comfortable with a wood based product. But it is done often, and often with great success.

01-16-2005, 02:00 PM
The solid wood subfloor, while strong, expands and contracts quite alot between seasons, that is why you at a minimum need some plywood on the floor. 3/8" is the minimum, since none of the 1/4" stuff is structural nor does it have the exterior grade glue necessary for under tile. For a mosaic, you wouldn't want to use Ditra, but other brands of isolation membranes could be used. The membrane helps to prevent the movement of the subfloor from messing with the tile. The little towers on the Ditra would make laying mosaic nearly impossible without some extra work, so probably isn't a good choice. Keeping all of the mosaic tiles level takes practice, plus alot of grout lines, so any flex will cause cracks if not done right.

Don Zorn
01-16-2005, 03:42 PM
You will need a minimum of 3/8" ext. grade ply on top of the plank flooring, then 1/4" CBU thinsetted to the plywood with non-modified thinset.

Recommend that you take Jim's advice and visit the John Bridge tile forum or the floorstransformed tile forum at http://floorstransformed.com. There are professional tile mechanics who frequent both of those forums who can guide you through what you need for a subfloor prior to installing the tile.

Don Zorn

01-18-2005, 12:46 PM

If it were mine, I'd add screw down 1/2" BC plywood and then thinset mortar (NOT premixed) 1/4" hardibacker, and then thinset (again, not premixed) the tile. If you want to save an extra 1/8", you could install Ditra matting atop the 1/2" plywood instead of hardibacker. Good luck and have fun...

01-19-2005, 11:03 AM
thanks all, for the input.

just visited the john bridge website again - my head is swimming with the myriad methods for properly laying a tile floor in a bathroom! there are certain points upon which no one seems to entirely concur.

i've already laid the 5/8" ply over existing subfloor, and have puchased 1/2" Durock (hardibacker) and not-pre-mixed thinset.

i'm perplexed (even after, or maybe especially after!) reading numerous posts on the john bridge website about this isolated membrane aspect.

some folks are adamant that one must be used and others eschew them completely.

some folks use ply + hardibacker + a membrane, some folks use only the ply + membrane OR hardibacker.

some folks insist Ditra must not be used with mosaic tiles, others question that wisdom.

some folks won't use ply at all.

so ... i'm a bit perplexed.

i want to lay a floor that will be compatible with tile, and have checked the joist spans and original subfloor specs, added sufficient plywood laid with room to expand / contract, and purchased hardibacker probably in excess of the thickness i really require.

however ... am i missing the point if i do NOT include a membrane in the equation, since this is a bathroom / damp setting?

[yes, i'll also post this over at johnbridge.com ...]

thank you all so much for your time and info,


01-19-2005, 01:04 PM

I know it can all be very confusing, but don't let it bother you. For a 10 x 10 bathroom, installing 5/8" plywood over your plank flooring and mortaring 1/2" Durock to that is plenty for a room that size; you do not need an isolation membrane. Something like that would be good for questionable applications where subfloor movement/flex is likely to occur. I always recommend a high quality thinset mortar such as Custom Building Product's Flexbond. It's a little more expensive than basic setting mortars, but it equals pennies per square foot extra.

Do take a look at the Q&A section of www.ceramic-tile.com as well. That site has very good free advice for general applications like yours - you can search the archives for specific advice. Do it once, Do it right. Good luck and have fun. Keep us posted.

01-19-2005, 06:09 PM
I agree with the last post. My original suggestion to use a membrane was not well thought out. A membrane is an isolation device to prevent slight cracks or movements in the substrate from coming through into the tile. It is useful when putting ceramic on a concrete slab, which is subject to hairline cracks, and sometimes has anti-fracture joints in it.

Over a wood subfloor, the main criteria is to develop enough total thickness to prevent any flexing under load.

In addition to the other references mentioned in this thread, the Tile Council of America ( www.tileusa.com ) put out an excellent handbook which can be ordered on line at reasonable cost.

Don Zorn
01-19-2005, 08:00 PM
Kavita - I am only a DIYer with four tile projects under my belt - currently working on the fifth - so take my advice with a grain of salt. Forget the isolation membrane - that is primarily for setting over cracks in a concrete floor or if you are tight for headroom and don't want the extra height that CBU will add to your overall height.

The 5/8" exterior grade plywood on top of your subfloor should be gapped by 1/8" in the field and by 1/4" around the perimeter of the room. Lay the 5/8" ply at 90 degrees to your subfloor and stagger the joints so that you don't have four corners meeting in one spot.

Screw the 5/8" ply only to the subfloor - not into the joists - every 8" in the field and 6" around the edges. Use deck screws or plated for corrosion resistance - not drywall screws. Thinset the 1/2" CBU with un-modifed thinset (the cheap stuff = $8/bag) - the purpose is to fill voids below the CBU, sao that there is no movement later on - NOT to adhere the CBU to the plywood. You can use a 1/4 x 1/4 square notch trowel for this step.

Immediately screw or nail the CBU as per the mfgr's recommendations while the thinset is wet. Leave 1/8" gap in the field and 1/4" around the perimeter with the CBU. After the CBU is set, stay off the floor for 24 hours. Caulk the perimeter of the room before setting tile.

To set the tile, use a good quality latex modified thinset - don't cheap out here. While setting the tile, work the latex modified thinset into the gaps in the CBU and use a margin trowel to push fibreglass mesh tape (special stuff for CBU) over the CBU joints as you are setting the tile.

Good luck! :) :) :)


01-20-2005, 07:41 AM
thanks guys, i accept your invitation to relax and keep it simple here!

your clarifications are most helpful. it seems much less esoteric now.

i'm curious about your suggestions re: screwing down the ply, don. could you further clarify something for me?

>> Screw the 5/8" ply only to the subfloor - not into the joists - <<

does this pertain only to subflooring beneath a tiling job, or is this what you also recommend for ALL ply subflooring over planks?

i.e., when you lay a subfloor that'll be covered by carpeting, hardwood, laminate, etc do you also screw the ply only into the base floor?

i'd imagined it would be ideal to grab the joists to the ply for extra hold, so i'm really interested to hear your reasoning. makes me think about the movement (over time) of joists, and how that movement effects the ply thus the tilework (in this case).

lastly, i'm still perplexed about the water resistance factor if i skip the membrane. does the durock provide a measure of moisture resistance? some folks talk about a moisture/vapor barrier ... anybody use these on a wood subfloor application?

i so appreciate everyone's help! i've blazed DIY projects solo for too long and learned the hard / frustrating / disappointing way enough now to really appreciate asking for advice. some of us are slow learners :o :)

best to all,


01-20-2005, 09:53 AM
For areas that get wet, a membrane is not a bad idea, especially with a wood subfloor. If you wipe up spills, it shouldn't be a problem on a normal floor. Moisture does get through the grout but it takes awhile. If you have kids that slosh water all over the floor each time they shower or bathe, then it may be a good idea. Tile should stay until you tire of it, not because of a failure. So, depending on the circumstances, waterproofing the subsurface helps. An isolation membrane is not necessarily waterproof - you need to follow the procedure to seal the butted up seams. It does provide crack resistance, regardless of whether you seal the joints or not, and is often used without sealing them.

01-20-2005, 09:55 AM
Hi Kavita,

As for screwing the plywood down, I would definitely screw into the joists and to the plank flooring to firm things up. Don't go too crazy with it, but make sure you DO NOT use drywall screws, but coated screws like prime guard decking screws.

While backerboard is not waterproof per se, it is greatly water and rot resistant (it is cement-based), so it will withstand any normal wear and tear that a bathroom goes through on a daily basis. When installing the backerboard, screwing it down atop of the thinset mortar with specific screws (e.g., Hardibacker or Rock-On brands) all over as recommended (usually 6" along edges and 8" in the field) is best. Then embed backerboard tape and tile away with the same or better thinset.

So, yes the Durock and your thinset mortar will provide plenty sufficient moisture resistance. In addition, if this bathroom is over a crawlspace, I would make sure you have 6mil or thicker poly plastic sheeting throughout the entire crawlspace to prevent excess moisture that could affect other areas of your house as well.

Don Zorn
01-20-2005, 07:22 PM
Kavita - This only applies under tiles.

I too thought this was strange and counter intuitive - but learned this tip from a couple of professional tile mechanics. Here's the reason:

If you screw the top layer of ply into the joists and there is any movement in the joists, it is more likely to transmit that movement to the tiles - which can lead to tile/grout cracking. In tile setting any movement of the subfloor is considered bad.

If you only screw the top layer of ply to the subfloor below, movement in the joists is not quite as likely to get transmitted to the upper layer of plywood - in effect decoupling the joists from the top ply. Albeit the bottom layer is still screwed into the joists and the top layer is screwed into the bottom layer so they are still coupled indirectly - but at least not directly.

I personally believe that if you don't follow this advice, it is not a catastrophe, but if you do follow it, it is just one more step that will only help to make your tile installation more successful. Good tile meachanics subscribe to this methodology - feel free to ask on the Floorstransformed ceramic tile forum.

In my opinion, you should be OK without waterproofing you bathroom floor before tiling as long as you don't leave standing water for long periods of time on the tiles.

My $.02 - worth the price charged!

Good Luck.


Don Zorn
01-24-2005, 04:47 PM
Kavita - If you are interested, read this article for more tips on how to place the underlayment (ie. top layer of plywood) relative to the sub-floor (bottom layer of plywood) in order to reduce tile cracking.


Don :)

01-25-2005, 04:51 AM
I understand what Don is saying, but Don, I somewhat disagree with you. Please hear me out... Atop of plank flooring, firmly securing the plywood is critical to ensure a stable substrate. Atop of that plywood, a tile underlayment should then be placed (e.g., hardibacker, durock, wonderboard, etc.) The specific tile underlayment is what needs NOT be secured to the joist, but obviously to the subfloor only the depth of the subfloor.

There is no way I would only secure plywood only to the plank flooring and not the structural timbers; that would be asking for trouble.

Don Zorn
01-25-2005, 02:16 PM
Greg - I hear ya. I thought the same thing - screw the underlayment right through the subfloor into the joists = nice solid floor = less tile cracking. But apparently I was wrong. It is even listed in the TCA handbook - only screw the underlayment into the subfloor. :)

Now this is for a plywood underlayment with plywood sub-floor. Maybe with plank subfloor it is different. That I am not sure about. :)


01-25-2005, 04:26 PM
Prior to putting down the plywood, make sure that the planks are firmly attached to the joists - it wouldn't hurt to add some screws, then nail (or screw) the plywood to the planks, avoiding the joists. If nailing, then use ring-shanked nails. If you hit a joist when doing the plywood, don't worry about it, but try to avoid them.

02-21-2005, 10:45 AM
first, thanks for all your responses last month.

can't believe it's been a month since last visit. left behind the tiling projects for other refurbishing tasks; now returning to the tile floor and have another couple preparation questions. (yes, also listing on johnbridge.com but the responses there can be somewhat daunting!)

i considered all your input and the ply subfloor is attached to what's beneath. i appreciate your musings, intuitive and counter-, on the subject.

i'm finally about to lay the durock ...

- would you please offer suggestions for a floor levelling product to add in a couple of areas between the plywood subfloor and the durock i'm about to lay?

there's a slight unevenness apparent in a couple areas now that the ply's down and i want to correct it. i've been told LevelBest would work, but i've heard also that a mortar mix is sufficient/preferred. your thoughts? your product recommendations?

- once the durock is in place, what do you suggest using to level the areas where the durock sheets meet and a depression exists? i understand the thinset might be sufficient for this, but i'd like to hear any of your ideas.

many thanks - i appreciate your help so much.


02-22-2005, 08:16 PM
Depends on how big the dips/hills are. From what I read, it is better to level after installing the cbu. If the depressions aren't too big, you can use thinset. Use the longest straightedge you have, the longer the better, and see how far off the floor is. Once the amount is known, that will help decide the best product to fix it. Self-leveling cement can be used, but it can be costly. Works great, though. Flows like pancake batter, sets quick, and makes a really nice flat floor for tiling.

02-23-2005, 04:48 AM
jim, jimbo, don, & greg,

guess this thread can close now but want to say thanks to you all for your ideas, suggestions, referrals.

all tile sites you recommended and materials therein have been most useful.

the tile council of america handbook (tileusa.com) is a great downloadable resource.

the article on underlayment specs (the TIleLetter article) is excellent - really helped me understand that perspective.

floorstransformed.com is really easy to navigate and get answers quickly.

johnbridge.com is, well, awesome and dense with information!

ceramic-tile.com also has a wealth of helpful info - unfortunately, i have a tediously slow dial-up account and the advertising slows down any desired mobility on my end.

anyway, i REALLY appreciate your time and patience.

see you when i tile the next bathroom - this time walls and backsplash!


01-05-2007, 10:17 PM
For areas that get wet, a membrane is not a bad idea, especially with a wood subfloor. If you wipe up spills, it shouldn't be a problem on a normal floor. Moisture does get through the grout but it takes awhile. If you have kids that slosh water all over the floor each time they shower or bathe, then it may be a good idea. Tile should stay until you tire of it, not because of a failure. So, depending on the circumstances, waterproofing the subsurface helps. An isolation membrane is not necessarily waterproof - you need to follow the procedure to seal the butted up seams. It does provide crack resistance, regardless of whether you seal the joints or not, and is often used without sealing them.

Here is my what my hubby that you maybe interested in....


check it out

08-26-2009, 04:30 PM
In addition to the great points discussed here, I would also note a couple of things about membranes like Durock Tile Membrane.

-totally waterproof and impermeable
-can lay directly over the existing flooring, so you don’t need to rip out old flooring
-super thin, so it won’t raise the profile of the floor.
-guards against tile cracking by giving some flexibility to the underlayment

Some more details here:


And some installation videos here:


http://www.youtube.com/watch?v=U7EgvohEcF8http://www.youtube.com/watch?v=Hve-sidUjRM (http://www.youtube.com/watch?v=Hve-sidUjRM)

Full disclosure: I work with USG, but this seems like a good addition to the conversation.

Robin Wisdom
09-24-2009, 10:15 AM
First, thank you so much for your web site. It is a wonderful resource for those of us who prefer to do our own work. I have learned a lot and I am so glad I found you before going forward. My house is 46 years old and on a concrete slab foundation. The garage portion (next to the kitchen) is 4 inches lower than the rest. We have tiled the kitchen with ceramic tile and now wish to continue the tile into what was the garage but will now be the laundry room. So after reading your message board I tried to come up with a plan for the sub-floor. How does this sound?
1. Build a structure of 2X3s with 8 inches of space between the boards. The 2x3s would be standing up on their side so that the height is actually 2 inches.
2. Lay down inch exterior plywood and screw into the 2x3s every 8 inches.
3. Lay down inch exterior plywood (the opposite direction) and screw to the inch plywood but not the 2x3s.
4. Apply un-modified thin set on top of the plywood.
5. Lay down inch Hardy Backer Board leaving 1/8 inch gaps between and inch around the outside edges. Screw it down with those big backer board screws and apply the mesh tape & thin set to the gaps.
That all adds up to 4 inches which will give me the proper height. Originally I was going to use 2X4s for the bottom structure which would have been 3 inches high, inch plywood, and inch backer board, for a total of 4 inches. But, after reading your message board I realized that I would not have 1 1/8 inch minimum under the tile. With the scenario above I will have
1 inches under the tile. Is that too much? Also, if you have a better suggestion please let me know. I eagerly await your response.

09-24-2009, 01:14 PM
Most garage floors are not made to be level...they usually have a pitch, either to a drain in the middle, or out towards the door. Your plan doesn't take that into account, or the possible irregularities. A better solution, but heavy work, would be to level it off with a mudpack. this is esssentially mostly sand with enough portland cement to hold it together (same as what's used in making a shower pan - 5-6:1 sand/cement). You could make this dead level at exactly the height you want. It's like working with wet beach sand. You could mix it right on the floor with a (special) hoe so you don't have to transport it far. The sand is dirt cheap, and you don't need much cement. Check out www.johnbridge.com (http://www.johnbridge.com). Your plan would work (except for the possible pitch and irregularities), but keep in mind, there is no reason to use thicker cbu than 1/4" on a floor except to match up heights. CBU has very little resilient strength, and will bend (and then hold after a while) to conform to any irregularities. Good ply is better, and more is better yet. You want ply with exterior or exposure 1 rated glue, and the sides C or better (no D side(s)). T&G ply would keep the short edges supported and save having to block there as well. This stuff starts to get expensive, and time and ultimate result means a mud floor should be cheaper, and maybe faster. If you have a boiler, it would also give you the opportunity to add radiant heat tubing to keep the space nice and toasty.

06-03-2010, 10:35 PM
I think cupping in Ceramic Tiles (http://www.bathroomfloortile.net) is the common problem and caused by moisture imbalance through the thickness of the wood.To control this u can to identify and eliminate the moisture source. ..this is the single solution of this problem....

08-28-2011, 08:56 AM

There is a lot of information in this thread and it is all over the place. A quick scan for "how to", can leave your head swimming with details and one wrong post you read can be the downfall of your entire renovation.

There are many different ways to construct a subfloor and many requirements that need to be met. I would suggest that anyone first visit the TTMAC and NTCA websites and look there for recommended sub floor assemblies - look for one that fits your home or install the closest.

Laying 5/8" sheathing, 1/2" ply, 1/2" cement board, ditra, Nobel TS, Flex Therm Cables and on and on all finely tune the sub floor make up.

When looking for answers you should understand what deflection criteria you need. What the requirements of the tile are for install (ie modified or unmodified). What's the thinest your setting materials can go to (ie 1/4", 3/4" etc).

This is not a simple question to answer.

I have to do many rebuilds for clients when I come to waterproof their shower. The number one failure I see in the DIY market is poor fastner and tool selection. You can't board these rooms many times with a re-chargable 12 volt drill. So many times I come in and it was the homeowners drill had no 'Balls' and the wall boards and sheathing is moving around like crazy.

Often we will prep these rooms for not as adventourous clients and leave the tile setting to them.


Bond Breakers.

Look up these terms and understand them first fully. Before learning how to build your new subfloor.

Good luck.


08-29-2011, 07:43 AM
With today's tile choices getting larger and larger and more and more homes being designed with open spaces - control joints, expansion joints and mortar fatigue are very important considerations.

Yet more research for you before planning your new subfloor.

This is a tricky process - the tile trade. Never have I found a one system fits all - ever.

Work with a PRO.

Look for those who are members of TTMAC or NTCA.

Hire someone with insurance.

Ask for a written description of how the floor will be built and tiled and what the time line will be. Before proceeding look into the proposed approached.

It's Easy. Fast. Quick. Weekend Project. are terms and phrases you will never hear me repeat in front of a client. Often online the advice you seek is mapped out this way.

Dig deeper.

http://i839.photobucket.com/albums/zz314/jfrwhipple/Framing%20Album/TileonPlywood_zpsab5ea69b.jpg (http://www.terrylove.com/forums/showthread.php?52614-Tiling-directly-to-Exterior-Glue-Plywood-(EGP)-Tiling-Tips-Pros-and-Cons)

http://www.terrylove.com/forums/showthread.php?52614-Tiling-directly-to-Exterior-Glue-Plywood-(EGP)-Tiling-Tips-Pros-and-Cons (http://www.terrylove.com/forums/showthread.php?52614-Tiling-directly-to-Exterior-Glue-Plywood-(EGP)-Tiling-Tips-Pros-and-Cons)


11-25-2013, 07:52 AM
http://i839.photobucket.com/albums/zz314/jfrwhipple/Terry%20Love%20-%20Random%20Pictures/WonderBoardLite-SubFloorPreperation_zps17af890e.jpg (http://s839.photobucket.com/user/jfrwhipple/media/Terry%20Love%20-%20Random%20Pictures/WonderBoardLite-SubFloorPreperation_zps17af890e.jpg.html)

Last Saturday I worked with my buddy prepping his daughter's bathroom floor for tile. There where a lot of upgrades to the bathrooms design and to cover the original sheathing we decided to go with a 1/4" layer of Wonder Board Lite. To install the Wonder Board I used Laticrete's 254 thin-set. We used 1.5" roofing nails (galvanized and a wack of them) and then tapped the seams of the boards with 4" mesh tape and more Laticrete 254.

Over this will go a Nu Heat Pad and some minor levelling....

The key points to this style of install is keeping the nails from hitting the floor joists below. Also keeping the board from bonding to the sides or bottom plates and tub are key. We kept everything back a good 1/4" to be safe.

http://i839.photobucket.com/albums/zz314/jfrwhipple/Terry%20Love%20-%20Random%20Pictures/Cleaningbondbreakeroffwonderboardlite_zps4aee9890. jpg (http://s839.photobucket.com/user/jfrwhipple/media/Terry%20Love%20-%20Random%20Pictures/Cleaningbondbreakeroffwonderboardlite_zps4aee9890. jpg.html)

Here you see me a few days later and I have just wiped the wonderboard lite down (after I vacuumed). Once the floor was clean and free of all debris I layout out the heating mat and cleaned both sides of this as well. Later I set it over the tub to dry. I do not want standing water anywhere - not on the mat and not one the floor.

After this was done I mixed up some Laticrete 254 thin-set. To make the mix looser I added 20% more water than spec'd. Laticrete 254 is not a low end thin-set. The choice of this premium setting material is because you do need to make a thin-set mix loose. So a great strong thin-set is still good when weakened by this over watering step. I have measure the strength of laticrete 254 in shear tests at this miz ration and the results are impressive. You can learn more about shear testing here (http://www.terrylove.com/forums/showthread.php?52833-ANSI-Shear-Testing-Procedures):

http://i839.photobucket.com/albums/zz314/jfrwhipple/Terry%20Love%20-%20Random%20Pictures/cleaningnu-heatpad_zps43e7d749.jpg (http://s839.photobucket.com/user/jfrwhipple/media/Terry%20Love%20-%20Random%20Pictures/cleaningnu-heatpad_zps43e7d749.jpg.html)

http://i839.photobucket.com/albums/zz314/jfrwhipple/Terry%20Love%20-%20Random%20Pictures/InstallingNuHeatPadoverwonderboardlite_zps4c6c9eca .jpg (http://s839.photobucket.com/user/jfrwhipple/media/Terry%20Love%20-%20Random%20Pictures/InstallingNuHeatPadoverwonderboardlite_zps4c6c9eca .jpg.html)

http://i839.photobucket.com/albums/zz314/jfrwhipple/Terry%20Love%20-%20Random%20Pictures/SettingNuHeatwithLaticrete254_zps182270bb.jpg (http://s839.photobucket.com/user/jfrwhipple/media/Terry%20Love%20-%20Random%20Pictures/SettingNuHeatwithLaticrete254_zps182270bb.jpg.html )

Set tight to the Wonderboard Lite Sub Floor. I'll be back this weekend to cover this floor with a layer of Strata Mat and do some minor levelling for the small mosaic tile.