Peregrine

We have a pool with a ~60' infinity edge. The water line, infinity edge, and dam wall are finished in dark brown porcelain tile. The grout at the knife edge has cracked under each of the mixes our tile man has used. I am looking for suggestions on alternative grouting solutions.

The pool can be seen in the attached photos.

Thank you in advance,

Jeff

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POOLMANinCT

i suspect to quick a cure, was it sheeted while curing?

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CALLAHAN POOL

How long does it take to crack after each new grouting?

Poolman

I see it's reversed...no watererfall. If the knife edge is out of the water and some of the tiles are exposed, I've seen some cracking due to expansion and contraction from the sun's heat. Try a flexible grout, like a sika product.

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Scott

Is this going to be expensive?
It's all relative.

Peregrine

It was not sheeted during cure.

The cracks are perendicular to the perimeter knife edge, at each intersection with the grout line that is perpendicular to that perimeter.

I am fairly certain that it is a heat related issue as it the cracks appear first on the sunny side, though they eventually appear on all three sides.

Jeff

All Decked Out

Peregrine,

It is most definately due to expansion, when the tile heats up from sun exposure it expands and when the water goes over the edge it quickly contracts causing the grout to crack.

I learned that the hard way with a 6 foot infinity wall covered in black slate.

use an elastomeric grout, or if it's really bad use a colored mastic and put silica sand over it before it dries (this is VERY hard to do)

Peregrine

Many thanks for the responses. They seem to be leading in the same direction as our other research.

One of the suggestions has been to strip the tile and apply a membrane, such Mulasticoat, and reapply the tile. This leads to the question of adhering the 16" x 24" tile to this substrate. Any thoughts.

Jeff

Poolman

Peregrine,

If you use Mulasticoat then you need to apply Scratchcoat before and after it. You thinset will bond to this. These products are made to work together, we've used them for years.

Scott

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Scott

Is this going to be expensive?
It's all relative.

Peregrine

Thank you.

Jeff

Darren CA

Dam walls are a problem with waterproofing... Both sides get wet and hense both positive and negitive hydraulic exposure to the waterproofing.... Water comes at the membrain from both the outside and the gunite side of the surface. Make sure any membrain you apply to the dam wall is specific to positive and negitive hydraulic pressure. I don't think multicoat is... Been a while since I looked at it but as I recall super blockade is a good choice

Poolman

I've never heard of super blockade. Who is it made by?

Mulasticoat is great but on a dam wall you shouold coat the whole wall boths sides then it will prevent water from penetrating the wall.

Scott

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Scott

Is this going to be expensive?
It's all relative.

Paolo Benedetti

Aquatic Technology Pool & Spa - Vanishing Edge, Infinity Edge, Knife Edge, and Perimeter Overflow Pool experts.

Thermal Expansion is your problem... these surfaces sit in the direct sun all day, then get water dumped on them, when they contract big time. Something has to give.... the tile will delaminate & the grout will sheer.

There should be expansion joints a MINIMUM of every 3 O.C. feet each way.

Our firm does not even bother to use any form of grout. We found that even epoxy grouts, polymer fortified grouts, & regular grouts will crack under the pressures.

Instead we use a sanded silicone caulking in all of the joints. The underlying surface is waterproofed with an elastomeric membrane, tile is then thin set, then after the full thinset curing period (14-28 days), the joints are cleaned, the special primer is applied, then the caulking is installed & tooled. It look just like grout & does not crack.

This is the same color matching caulking that is used to set sinks, where sinks meet granite or ceramic tile.

Or product preference is Latisil by Laticrete. be sure to get the special primer, because without it in underwater & wet location applications (showers & tubs), it will just peel right out.

AVOID Mulasticoat at all costs! They do not stand behind their products! Left us hanging with $30,000 in repair costs due to their products delaminating.