We are finishing our basement and will have tile floor. As is the case with most concrete basement floors there is a long crack. Maybe 1/4" wide and total of about 40 feet. I want to fill it before they put the tile down.

There are tons of options online. Epoxy, hydraulic cement, poly, etc.

Anyone have a fairly inexpensive recommendation.

Look at Henry's products.

I used to use Henry's floor float leveling compound before installing vinyl flooring.

It was easy to use, and not very expensive.

Before you go doing a Joe Homeowner fix you might be well-served by having professionals examine it to determine whether there's a serious issue with the foundation that should be addressed.

A forty-foot-long crack 1/4 in. wide is a pretty serious crack.

We typically used Ardex Feather Finish for leveling and gaps up to 3/8" or so. If it's a crack from settling which is no longer moving you should be fine, but if the slab is expanding and contracting from humidity, temperature, etc they will likely continue to do so and cracking the tile. If this is the case IIRC there is a flexible membrane (maybe 24" wide) that can be adhered over the crack after filling it. Then lay the tile.

When you say "before they put the tile down", who are they? If they are professional tile installers, why aren't they doing what needs to be done to prevent the new tile from cracking along the floor's crack?

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Originally posted by ensigmatic:

A forty-foot-long crack 1/4 in. wide is a pretty serious crack.

You'd be hard pressed to find a basement floor in New England without cracks similar to this. It's not structural. Basement floor is poured after foundation. This crack is probably 1/4" at it's widest. Most of it is hairline. I should have said that.

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Originally posted by ridewv:
We typically used Ardex Feather Finish for leveling and gaps up to 3/8" or so. If it's a crack from settling which is no longer moving you should be fine, but if the slab is expanding and contracting from humidity, temperature, etc they will likely continue to do so and cracking the tile. If this is the case IIRC there is a flexible membrane (maybe 24" wide) that can be adhered over the crack after filling it. Then lay the tile.

I'll look into the membrane. It is a fairly new house. It's definitely from settling. The house is on a hill, so the foundation is on big concrete footings. We've dehumidified constantly and don't get much more moisture from the basement. House is just about a year old.

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Originally posted by trapper189:
When you say "before they put the tile down", who are they? If they are professional tile installers, why aren't they doing what needs to be done to prevent the new tile from cracking along the floor's crack?

I have a contractor doing the basement. I didn't really ask him about the crack in the floor. I'm sure he would do what needs to be done, but it's probably a lot cheaper for me to fill myself. Anything a contractor does comes with a price. Some things are DIY and no problem. Filling a crack seems pretty simple if I have the right stuff. I've used epoxy kit to repair a concrete foundation wall, just as good as the $700 Crack X guys and cost me about $70. But I'm not sure epoxy is the right thing for the floor.

I do concrete repair on a commercial scale in New England. I’m actually going to be in Boston for the next month. If you’d like I’d be more than happy to take a look at some pictures or in person and perform the labor for free. Depending on the repair I may have materials sitting in my shop either reply on here or shoot me an email.

The tiler had better not be applying tile directly to a basement floor.

A decoupling membrane like Ditra should be used in almost every situation.

I'd disagree that cracks in basement floors happen in every home in New England. I've been in plenty with no cracks. It's more accurate to say that they aren't that big a deal.

If you want to fill it yourself, I'd recommend Sikaflex 1a.

Regardless what you use to float or repair the floor, don't put tile down until you've installed an uncoupling membrane. There a numerous vendors that make this stuff ( Schluter Ditra being one of them).

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Originally posted by arcwelder:
The tiler had better not be applying tile directly to a basement floor.

A decoupling membrane like Ditra should be used in almost every situation.

I'd disagree that cracks in basement floors happen in every home in New England. I've been in plenty with no cracks. It's more accurate to say that they aren't that big a deal.

If you want to fill it yourself, I'd recommend Sikaflex 1a.

Assuming there are multiple cracks in the floor, wouldn't it make better sense to just float out the entire floor. That would also provide a nice flat surface overall to install tile on top of.

Thanks guys. I’ll check with the contractor on his plan for the floor. Ffemt: I’ll get some pics and shoot you an email tomorrow.

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Originally posted by frayedends:
Thanks guys. I’ll check with the contractor on his plan for the floor. Ffemt: I’ll get some pics and shoot you an email tomorrow.

I would let the tile guys deal with it, that's what they do everyday for a living and know how to deal with it. Chances are they'll just float the tile right over the crack......

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Originally posted by arcwelder:
The tiler had better not be applying tile directly to a basement floor.

A decoupling membrane like Ditra should be used in almost every situation.

I'd disagree that cracks in basement floors happen in every home in New England. I've been in plenty with no cracks. It's more accurate to say that they aren't that big a deal.

If you want to fill it yourself, I'd recommend Sikaflex 1a.

Now I'm a bit concerned as the builder just replied that they always do tile right to concrete and it's not a problem. Not sure what to do now since he is starting in 2 weeks and we already put down the deposit.

Tell him you’d like the membrane installed first. Period. If that’s a problem, review your contract.

Arcwelder hit the nail on the head.

In the south we call his membrane "crack isolation membrane " for 1/4 crack it's a must use.

Sikaflex product is top notch. You can do this yourself if you are inclined. Read the instructions for a 1/4 inch you would likely grind each side of the crack to form 'V' then tool in the sika. The sika will flex with the slab movement and covering with isolation membrane will allow the thinset to bridge the crack when it moves.

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Originally posted by frayedends:
Now I'm a bit concerned as the builder just replied that they always do tile right to concrete and it's not a problem. Not sure what to do now since he is starting in 2 weeks and we already put down the deposit.

Easy. If he wishes to be paid in full he'll heed your request and install a membrane. You control the job, not the other way around. No way would I allow tile to be installed directly on the slab. Know how many half-ass contractors I've seen install cement board in a shower and only waterproof the corners? Fast and cheap is what a lot of contractors are looking for when it comes to tile installation.

We are all set. He is going to install the membrane at our request. He usually does not and has had no issues. I should note that my girlfriend has been using him for over 10 years as a realtor and he has never had a complaint. He has a great reputation and I’ve seen his work a bunch of times.

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Originally posted by bigdeal:

quote:

Originally posted by frayedends:
Now I'm a bit concerned as the builder just replied that they always do tile right to concrete and it's not a problem. Not sure what to do now since he is starting in 2 weeks and we already put down the deposit.

Easy. If he wishes to be paid in full he'll heed your request and install a membrane. You control the job, not the other way around. No way would I allow tile to be installed directly on the slab. Know how many half-ass contractors I've seen install cement board in a shower and only waterproof the corners? Fast and cheap is what a lot of contractors are looking for when it comes to tile installation.

Yup.

The "It's how we always do it, it's never a problem" bit is not acceptable. Does he come back and fix it when it cracks? I have a feeling their "warranty" is limited. He's probably long gone, that's why it's not his problem. The correct response to "I'd like a decoupling membrane" is "OK, here is the price."

If you need a tiler, I know a few, but they are probably busy, so it wouldn't be right away.

If your contractor is "old school," he needs to wake up to current materials and techniques for construction, there have been many improvements over "that's the way we've always done it. Decoupling membranes are one such advancement, and he should be using them.

I like to actually see it installed, until I trust someone to always do it. I had 2 tilers charge for it and not install it.

I love Ditra and use it along with many other Schluter products.
Kerdi boards are great to work with.

Good deal. You're paying people to do a job right and that's what they should do. The downside is you have to learn what done right means. I can screw up a job for free, so it kills me to pay someone else to screw it up.

Cracks in concrete slabs are nothing new and normally they are planned for by installing contraction joints either while the concrete is wet or cutting them with a saw after the concrete has cured. While the concrete cures, it shrinks and the theory is the cracks will happen at the contraction joints. If it goes right, you can lay tile next to the joints after the concrete has cured. However, if you lay tile over the joints, the tile will probably crack. Also, if the concrete cracks in unplanned places after the tile has been laid, the tile will crack. A decoupling membrane turns the tile into sort of a semi-floating floor. The membrane is adhered to the concrete and the tile is laid over the membrane. It's a sandwich with the membrane providing flexible cushion if the concrete moves slightly.

That's my layman's understanding anyway.

Most houses in Florida have concrete slab floor's and I've had two relatively new houses down here with concrete and tile cracking problems. These houses both have stem walls that are then filled with dirt to bring the finished floor level above the flood elevation. They compact the dirt and then pour the slab. Settling happens over a few years and the slab cracks. I didn't have the houses built, so no membrane was used. It was used when I had the tile replaced.

On the other hand, the house we are living in now was built in 1974. It's a single story ranch and I figured if the floor hasn't cracked in the last 45 years, it would be safe to install the tile without a membrane. Besides, by the time it does, my wife will want something else.