Laying tiles (mosaic) outside advice sought.

[Nic_the_Urchin]

Hi guys,

I know this isn’t woodwork related but seeking some advice on the off chance. Partner wants to do a tile mosaic on a brick wallabove a brick bbq (that she just roped us into building )
I think we need a heat proof thin set adhesive that is also exterior. But I can’t seem to find anything.

im out of my wheelhouse here so any advice appreciated. any suggestions about which adhesive/grout/sealants/backer boards etc gratefully received.

cheers
nic

 

[Bingy man]

I’ve had a look online and there’s a multitude of heat resistant adhesives designed for fireplaces and stoves etc but it seems your problem is the ( exterior part) unless you can find a purpose made product to suit your needs then maybe split your task into 2 parts . Eg a suitable heatproof adhesive for your tiles then seal the tiled area with a waterproof finish once the tiles are set and grouted. Of course the waterproofing would itself have to be suitable for high temperatures which may put you back where you started. Good luck and let us know how you get on .

 

[Richard_C]

I wonder if embedding them in fire cement might work. Fire cement becomes the fix and the grout. You can do a trial, get a brick, spread some fire cement on one face, embed a few bits of tile, let it dry/set for a day or two. Next time you do a roast dinner or make a cake put the brick in the oven and see what happens. If it's intact, put the cooled brick on the floor of your shower for a few days so it gets wet when you get clean. If it survives that, you have an answer.

 

[Pedronicus]

I wonder if embedding them in fire cement might work. Fire cement becomes the fix and the grout. You can do a trial, get a brick, spread some fire cement on one face, embed a few bits of tile, let it dry/set for a day or two. Next time you do a roast dinner or make a cake put the brick in the oven and see what happens. If it's intact, put the cooled brick on the floor of your shower for a few days so it gets wet when you get clean. If it survives that, you have an answer.

Fire cement is not weather proof nor a particularly good adhesive.

 

[screwpainting]

Hi, contact the tech department of Ardex UK and seek their advice.

 

[recipio]

Just a word of advice on mosaic tiles. I did a splashback in my kitchen and thought it was a pretty good job. Then I turned on the overhead task lights and found a lot of them had sagged in the middle. Just a fraction and not visible until the lights went on. Can't help with the adhesive but I would use a 'hawk ' or similar to ensure they are bedded in evenly.

 

[MikeJhn]

I would use this or something similar: Easyfix KEM-PSC-380-EF Polyester Resin 380ml - Screwfix

or this: Epoxyset 105 Standard Concrete Repair 4kg | Toolstation

 

[Nic_the_Urchin]

Thanks everyone. my girlfriend started before we had a response (impatient/excitable)* delete as appropriate.

we went for fireproof adhesive Victas HB60 and a heatproof grout. We’ll use a sealer on top after. Hopefully it will hold up. It’s pretty rustic fun and colourful so hopefully any problems can be patched after.
here is an in progress pic if anyone is interested in seeing …

Neither of us have laid brick before… it shows. I’ll be happy to get back to making my toolchest.

cheers
nic

 

[Nic_the_Urchin]

More progress…starting to come together

 

[Bingy man]

A decent job and loving the bright colours

 

[Agent_zed]

my understanding of these things is that the main thing about exterior grade grout/tiles etc is that it is frost proof. That is the main concern. Interior grade stuff is going to be waterproof as it is for use in a shower etc but unlikely to be much frost in there.

so if I were you i'd just put a cover over it in the winter and not worry about it too much. The chances are it'll be fine anyway as even if something isn't rated as exterior it often means they just haven't done the necessary tests to be able to say it and/or don't want to guarantee it will work.

Or build a tiki hut style roof over it

 

[Nic_the_Urchin]

Or build a tiki hut style roof over it

Please don't suggest that to her ! Ive got my own projects to get on with

 

[Matt_0222]

I’m wondering if it might be sensible to use a brick waterproof sealant on the rest of the brickwork (ie. On the reverse face and top of the brick work. That way during the winter the bricks won’t get damp or wet in the same way - thereby protecting the adhesive from some of the impact of the weather. You’ll then only have to worry about frost on the outside and not damp bricks freezing on the inside.

 

[Nic_the_Urchin]

I’m wondering if it might be sensible to use a brick waterproof sealant on the rest of the brickwork (ie. On the reverse face and top of the brick work. That way during the winter the bricks won’t get damp or wet in the same way - thereby protecting the adhesive from some of the impact of the weather. You’ll then only have to worry about frost on the outside and not damp bricks freezing on the inside.

I did actually wonder about that - we tiled the top of the bricks to protect them a little bit was unsure about sealing the back. Will it allow the brick to “breathe” (do they need to?) any thoughts/knowledge appreciated.

 

[MikeJhn]

Tiling the top of the bricks is a good idea, but not sealing the back any water that has been adsorbed into the bricks needs to be able to condense away as water vapour from the surface to prevent the brick from blowing apart when the absorbed water freezes.