Tile Adhering to Slightly Damp Cinder Block

[Pizza Fermentor]

I am in the process of tiling my oven base. The top tile is done, and I'm working my way from the top down with the side tiles. Unfortunately, no updated photo yet.

We have had an ungodly wet summer. I dry-stacked my blocks, and filled every other core hole with concrete. As the rains have continued, the block has become wet. It appears some of the cores have filled with water (not completely, but to some extent) because there are a few points at the cinder block/base junction that's always wet. Water seeps from the inner block hole to the outside.

In the picture below you can see that the bottom mortar line essentially never dries out.



My question - Can I tile and grout over this lower section while it is in it's present state? Do I need to place a space heater in the wood compartment and try to dry the thing out?

It is now mid-October in North East Ohio. It's getting colder, and wetter. I have been installing my tiling while underneath a tent, and covered the oven with a tarp after I stop working. I see no end to our rain, until it turns to snow.

Any feedback those experienced with cinder block tiling is appreciated. Is outdoor-grade adhesive and grout like concrete, and cures even while in the presence of some damp block?

I'm banking on my water/block phenomena disappearing once the whole thing is tiled and grouted (all the dry-stack crevices will be sealed).

[david s]

It depends on what type of adhesive you use. Is it cement based or acrylic? You should really seal the surface with a tile primer prior to gluing the tiles on.

[brickie in oz]

Originally Posted by Pizza Fermentor

I'm banking on my water/block phenomena disappearing once the whole thing is tiled and grouted (all the dry-stack crevices will be sealed).

Work with it and not against it.
Drill some holes in the base and leave them there even through the tiles so if any water does get in it can get out again.

[Pizza Fermentor]

Originally Posted by david s

It depends on what type of adhesive you use. Is it cement based or acrylic? You should really seal the surface with a tile primer prior to gluing the tiles on.

Primer? Where were you a couple days ago?

It's too late, since a lot of the tile work is already done. I guess I'll know in the spring if it bonded well.

[brickie in oz]

Thats a new one for me, Ive never heard of tile primer?
Mind you Ive only been in the building trade for 40 years....

The tiles should bond ok to the concrete block and render with just tile adhesive.

[david s]

A primer enhances adhesion to a range of substrates prior to tiling. I use a product called Dunlop Primer and additive. It can be also added to tile grout to add some flexibility and to reduce porosity (more waterproof).The reason I started using this product was because a small tile fell off the decorative arch on one of my first ovens. I now use this all the time and haven't had a failure since.

[brickie in oz]

Yeah Ive used that Dunlop stuff myself and its nothing short of a gimmick just to boost sales.
It wasnt needed until Dunlop decided it was, just my opinion.

[david s]

Try this link. Davco also recommend a sealer. I believe it does enhance the adhesion, from experience.

http://www.rossettotiles.com.au/surfaceprepguide.pdf

[brickie in oz]

Its still a gimmick.
They have stuck tiles to masonry for thousands of years without any problems and lots of them tiles are still stuck there.

Now, all of a sudden big companies say you need a sealer?

[david s]

Lots have fallen off too.
I believe Bondcrete is also used for the same purpose.