Question on VCT installation - Contractor Talk - Professional Construction and Remodeling Forum

Dan V. · 05-01-2009, 09:14 PM

I've got a good sized commercial job coming up in June where the customer wants VCT installed on the diagonal in a very large L-shaped room. To make it more interesting, it will also be laid with an 8x8 64-tile repeating pattern. My question is this. He wants it laid on the diagonal, but the control joints in the slab are not. Can this be done without the floor ultimately failing?

Anyone ever run into this before?

BKM Resilient · 05-02-2009, 01:36 PM

Control joints, properly done won't affect your layout.

Dan V. · 05-02-2009, 03:48 PM

What is considered "properly done"? These are cut 1 1/2 inch into the slab, which was poured approx. 4 months ago.

Mike Costello · 05-02-2009, 04:23 PM

If the slabs gonna move its gonna move. It will not make a bit of difference hw the VCT is layed out.

BKM Resilient · 05-02-2009, 05:39 PM

I agree with Mike. What creates problems that show through on the control joints is how well they prepared the job for the concrete. In California we have constant earthquakes and so even 100% perfect concrete procedures will fail when the whole slab is bouncing up and down like your kids used to do on their beds. I did a Walmart in Pico Rivera and we found out as we were prepping the job that some rocket scientist in Arkansas decided that reinforcing steel bars in concrete was superfluous so they deleted them from the job specs. Sure, so long as no one ever rolls a cart with more than 50 lbs across the joints! Just imagine what the scissor lifts and pallet jacks did.

The best you can do is make sure all the joints are cleaned and vacuumed out so your Ardex Feather Finish gets a good bond and fills the entire void and not just laying over layers of dust, mud and whatever else winds up down there. I always make two passes over a saw cut. Depending on how filthy and rough the slab is I sand the floor before or after patching.

So laying the tile square, on a 45 degree angle or upside-down for that matter isn't relevant to your treatment of the joints and how structurally sound the slab itself may be.

Dan V. · 05-02-2009, 05:46 PM

I appreciate the comments. In the past when I've done VCT, I always try to lay it out along the joints. Naturally, there are times when it's not always possible, but I've not laid directly over joints on purpose.

The good news is that the concrete boys did an outstanding job, both before and after the pour.

BKM Resilient · 05-02-2009, 06:37 PM

Quote:

Originally Posted by Dan V.

I appreciate the comments. In the past when I've done VCT, I always try to lay it out along the joints. Naturally, there are times when it's not always possible, but I've not laid directly over joints on purpose.

The good news is that the concrete boys did an outstanding job, both before and after the pour.

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I only consider the joints on a layout with plywood OR if there's significant "heaving" across the joints on a big slab like a supermarket or Walmart/Target. In the desert areas East of here the temperature changes are so dramatic that the concrete tends to curl up at the cold joints and saw cuts as the slab expands. In some of these cases we are expected to float out the 1/4" saw cuts with a 20" floating trowel. And they're not expecting to pay extra! If I think I can get away with it I'll just fill the hole with a 6" patching knife and that's all she wrote. With the slab bouncing and curling under the kind of stress that is normal there's really no serious cure for what ails them so my patch is really just a superficial attempt to get paid.

Funny they can do those exposed concrete slabs to perfection like you see in Lowes, Home Depot, Walmart and Costco but just about any VCT job they allow the concrete guys to finish the job drunk, in the dark with 2nd hand hockey sticks. Don't worry the tile will hide it!

Dan V. · 05-02-2009, 09:06 PM

Quote:

they allow the concrete guys to finish the job drunk, in the dark with 2nd hand hockey sticks. Don't worry the tile will hide it!

Mike Costello · 05-03-2009, 09:28 AM

Lol , when a slab is sucky I always say the crete was dropped from an airplane

Floordude · 05-03-2009, 12:43 PM

All expansion management in the concrete, must be honored in the finished flooring.

You will chase the dragon, until it is honored.

PrecisionFloors · 05-03-2009, 03:14 PM

Quote:

Originally Posted by Floordude

All expansion management in the concrete, must be honored in the finished flooring.

You will chase the dragon, until it is honored.

This one. Go look at a well done install in a shopping mall

Floordude · 05-03-2009, 06:57 PM

Quote:

Originally Posted by PrecisionFloors

This one. Go look at a well done install in a shopping mall

The mall close to me here, went from ceramic that was there since it was built in 78, to carpet tiles and very little floating laminate in the crossovers.

You don't see much VCT anymore, around here. My daughters school has it though,
Cracks at every crack management joint, too.

Dan V. · 05-03-2009, 10:30 PM

So, should I explain this to the client and tell him that his floor is destined to crack because of the way he wants it laid? As I've said, I'm already leery of the diagonal layout because of the joints, but I haven't shared that with him yet.

BKM Resilient · 05-03-2009, 11:05 PM

Quote:

Originally Posted by Dan V.

So, should I explain this to the client and tell him that his floor is destined to crack because of the way he wants it laid? As I've said, I'm already leery of the diagonal layout because of the joints, but I haven't shared that with him yet.

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Laying the tile square or on an angle-------how does that make a difference in the structural integrity of the subfloor?

BKM Resilient · 05-03-2009, 11:29 PM

Quote:

Originally Posted by Floordude

All expansion management in the concrete, must be honored in the finished flooring.

You will chase the dragon, until it is honored.

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How would you go about honoring the expansion management in the concrete for the typical LARGE commercial resilient job?

Dan V. · 05-04-2009, 06:36 PM

Quote:

Laying the tile square or on an angle-------how does that make a difference in the structural integrity of the subfloor?

Makes no difference to the structural integrity of the subfloor. If I lay it square, I can lay the tile along the joints rather than over them. That way, if (when) the slab cracks along the joints as designed, the crack will appear in the seam of the VCT. Laid on the diagonal, I have no choice but to go over the joints, which will result in cracks across the tiles themselves.

BKM Resilient · 05-04-2009, 08:43 PM

Quote:

Originally Posted by Dan V.

Makes no difference to the structural integrity of the subfloor. If I lay it square, I can lay the tile along the joints rather than over them. That way, if (when) the slab cracks along the joints as designed, the crack will appear in the seam of the VCT. Laid on the diagonal, I have no choice but to go over the joints, which will result in cracks across the tiles themselves.

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I know you mean well and that idea seems to make sense but it's against some very basic principles of floorcovering. The only way to accomplish what you want would be to start on a joint and then cut every tile at every subsequent line because there's no way in hell they cut that concrete exactly where a full tile is going to fall. We don't do it that way for good reasons. No professional vinyl flooring guy would EVER try to place a seam on the weakest point of the subfloor, designed to fail. Now instead of one row of tiles cracked and showing through the failure of the concrete work you've got two rows of tiles to replace. Have you ever seen VCT cut in the middle of a floor for no apparant reason? Just about any commercial spec book is going to demand FULL TILES throughout the field so you ain't even allowed to do that cutting!

Prep the joints right and that's all any customer can ask of you. You've already seen that the concrete guys are pros as their work looks sweet. That tells you that they know what they're doing and any cracking or shifting in the slab is going to be minimal. Go ahead and lay it the way they designed it. They'll be very happy. Don't worry about it.

Dan V. · 05-07-2009, 06:57 AM

Thanks, BKM. You're right of course. I'll just have to trust that the slab is as good as it looks.

The vast majority of the work I do is residential, which doesn't call for VCT. Ceramic, natural stone, T&G wood, laminate I can do all day with no worries. I think I'm just overthinking this install. The client is a friend/business associate and I want the job to be perfect.

BKM Resilient · 05-07-2009, 10:26 PM

Quote:

Originally Posted by Dan V.

Thanks, BKM. You're right of course. I'll just have to trust that the slab is as good as it looks.

The vast majority of the work I do is residential, which doesn't call for VCT. Ceramic, natural stone, T&G wood, laminate I can do all day with no worries. I think I'm just overthinking this install. The client is a friend/business associate and I want the job to be perfect.

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These are the most basic pointers you will appreciate if you follow them. You won't find a REAL pro who disagrees.

#1 Use a sander (floor buffer with a sanding disk attachment, heavy grit. --rent one) to get the concrete as smooth as possible. Yes, you NEED to do this even on a very well finished, brand new slab. It's how we do it.
#2 Use a wax based Kleen sweep with a FINE broom in proportion to the amount of dust you raised up in the sanding process. If you don't have a FINE broom shopvac the whole area after you've swept it the best you could with whatever broom you ordinarily use. The floor HAS to be tits clean. It wouldn't hurt anything to damp mop it. (we don't go that far)
#3 Use a shopvac around the walls and in any cracks or hole. Nothing sticks to dust.
#4 Use Ardex Feather Finish with Marshalltown patching trowels.
#5 Use Armstong or Henry's Clear Thin Spread Adhesive -----1/32" notch size is plenty. You know why? Because you've cleaned and prepared the floor so well in #1-4 that you're not trying to hide any sloppiness with "extra" glue. Too much glue is the WORST possible solution to any problems you might imagine. #1-4 have already solved those problems, you see. It's ALL about floor prep.

Laying the tile is the fun and easy part.....almost foolproof if you already know how a tape measure and a chalk line work!

gideond · 05-08-2009, 05:58 AM

If you are that worried about it, convince them to use a proper expansion joint. Schluter does make a Dilex expansion joint for resilient goods. You will see the line in the floor though.