Can i use mortar to level a floor

Thin-set is designed with typically a high amount of cement and does not include ingredients designed to make it flexible or keep it from flowing away from where you put it. The most likely dangers of using it too thick are cracks see photo , delamination, and lippage. Please note that the thinset being shown as a patch in the previous pictures is one designed to be used on plywood an ANSI A If you try to do that with an el-cheapo thinset, good luck.

Apart from just the physical challenges, there is a bigger picture challenge to be considered. The reason substrate flatness requirements and large format tile definitions are in the Handbook aren't a plot by greedy installation products manufacturers to shake every dime out of your pocket, they're a tool for you to use to educate your customers on what constitutes a flat substrate and what is required to have a long-lasting tile floor installed on it and to get paid for your extra work.

If you want to use thinset for leveling and large format tiles, that is entirely your call. However, if you have a failure and you've used a product in a way it wasn't intended, how to fix it will also be entirely your call. Agreed, but the FF specs also cover manufactures too Other then my own mud jobs I would be happy.

I agree with you completely, Jim. Reality door heights, meeting up with adjacent floors, etc While I agree that industry standards are necessary, a good many of them are "pie in the sky". To me, it looks like that pic may be outside, which would make it a whole different animal.

Like the rest of you, I've also used thinset to flatten out floors and walls. Still waiting for that first failure on account of it too You guys would like my slabs ; So would I. Sadly I have not had opportunity to tile over one yet :.

In a rather recent development, it was reported at a tile industry committee meeting that the concrete industry and the tile industry had come to an agreement that the concrete industry simply was not able, in most cases, to provide the flatness required by the trend toward large format tile.

And it was apparently also agreed that FF and FL don't really have any meaning at all to the tile industry. The solution being worked out is just to agree upon that, have the GCs or specifiers require that if the tile industry required flatness cannot be met, the slab would simply be dropped in the tile areas and bids would be accepted on mudding the floor to spec or an allowance would be provided for the tile installer or others to make the provided concrete surface flat enough for the tile installation.

Sounded like a reasonable plan to me and I hope it becomes the accepted norm in both industries. Thanks for the info CX, That does sound like a real solution, The money that is saved by hiring good finishers would offset the floor leveling. Also place responsibility on the tile guys which would avoid finger pointing.

As long as the installer can get allowances I am all for that idea. Is this related to the medium bed issue?

Pardon my ignorance on the process of laying concrete Do the humps generally form in the finishing process? If so, it seems like screeding the concrete level and just barely putting a finish on it would keep it from having humps pushed into it. It would give a better bonding substrate than a slick trowel finish too. Any practical reasons that can't be done in areas to receive tile. It all just seems like a cop out by the cement heads to me Shutting down a hospital to reinstall cracked tiles isn't a cheap fix.

I'm not unsympathetic to the fact that you're asked to 'fix' a lot of messed up substrates to accept increasingly larger tiles. There are some great patches and self levelers available that make life much easier when it comes time to set the tiles. Your challenge is getting paid for using them which is why the Handbook is a great educational resource. I think the "a-ha" there Dan is that they used a cheaper mortar for levelling.

I bet if they used say, LFT to do that, they would've been ok. Just saying for arguments sake. The finishing does not effect it that much, after you screed there can be rocks and such that got kicked up above the surface,they would need smoothed down into the cement. Problem I just thought of is there would not be much depth for mud,,the concrete would have to be close to final floor height just to place walls and stuff on it, door heights,cabinets etc..

And you cannot very well do the mud before many other trades are done with what they do,if for no other reason then simple scheduling. The floor levelers would need to level the floor before subsequent construction..

And worse of all.. What am I missing here? I do think it is a bit of a cop out by concrete finishers. One day I'll find the pics. I get tired of "well that's the best they said they could do, what can you do to fix it? My standard answer is "ya know concrete it's a funny beast--way easier to flatten and level while its still wet".

I seldom think to flash or flatten the plywood subfloors with either slc or thinset. I'm sure I've done it a couple of times when things were really ugly. But always just made it up at the setting of the tile. I began tile setting in Phoenix, in which city the cement finishers were predominantly Union at the time. House slabs were excellent. I know it can be done. I've seen it and lived it. They sort of screed it, but they don't tamp it.

I've never seen a hand tamper around here. Nobody knows what they are. They bull float it too early and jump on it with a troweling machine, again, too early. Then they walk away. Recently I got into it with a construction manager for Perry Homes, one of our largest home builders.

He told me they always meet that standard and that his setters don't have any problem with it. John, it was actually installed over a membrane, there was no slab crack noted. We have mudded up many floors that way, some builders would even lay masonite over the mud to protect it if they wanted to wait to tile it. Sure, it costs more money but it sure makes for a flatter floor. In fact, most manufacturers indicate in their product literature NOT to use thin set mortar to level or flatten the floor or wall.

The reason manufacturers caution installers against this practice is that thin set mortar was never designed to be used to fill in low areas. When used as filler, especially when it is thicker than the recommended thickness after the tile is embedded, t he mortar can shrink at different rates during its curing process. When this takes place, some of the tile surface that looked perfect when installed, will look extremely irregular in a couple of days as evidenced in the photo above.

If you're in a situation where you must prepare the substrate so it is tile ready, what will be your product of choice? I hope you'll never use thin-set or large and heavy tile formerly medium bed mortars to fix the floor or wall substrate, whether it requires filling the low spots or feathering out the high points in the floor.

Your best choice will be the proper flash patch or self-leveling underlayment with primer to make these corrections. When repairing walls, a good quality flash patch should work well. You don't become a tile installer or a business owner overnight. It takes time, enthusiasm, pride, reliability, respectfulness, a willingness to learn, and dedication. No two jobs are the same; each one has its own unique nuances. As a qualified installer, you need to be able to communicate how to deal with those nuances and qualify yourself to not only meet but exceed expectations.

Being qualified will exponentially increase your value and you will have endless opportunities. Crossville's Latest News and Views. Daltile's Trend Hub. The title of this blog is a frequently asked question that tile installers have considered when a concrete or plywood substrate has dips or humps in the floor.

Because mortar will stick to the concrete slab and the wood subfloor, and mortar will stick to mortar, then it would only make sense that mortar would work for leveling or patching, right? Well, the answer is actually no. Mortars cannot be used to level or patch a floor — ever! Once the mortar is cured, each new layer becomes one with the previous layer; this makes the mortar unstable once curing has occurred.

We recommend choosing a self-leveler or patch product instead. MAPEI makes several different levelers and patches to accommodate a variety of issues that an installer may encounter on a tile-installation project.

The most versatile self-leveler is Novoplan 2 Plus , a high-strength, cement-based underlayment and repair mix for use over interior concrete, plywood and other approved floor surfaces. Self-leveling compound is the best solution, by far but if that is not the option than I suggest one of two options: first would be not to touch anything; yeah it is damaged and uneven but since it is a workshop maybe you shouldn't care about it.

Another solution is to make a cement screed which then would be covered with some flooring. Also instead of screed you can pour thin concrete slab, but concrete should be made out of fine small pieces gravel.

Sign up to join this community. The best answers are voted up and rise to the top. Stack Overflow for Teams — Collaborate and share knowledge with a private group. Create a free Team What is Teams? Learn more. Can I use mortar to roughly level a basement floor for workshop? Ask Question. Asked 6 years, 5 months ago.