tiling over wood and concrete

[christone]

Hi

I'm not sure about the best preparation to tile over an area that has both wooden floor and concrete (with underfloor heating in). I'm thinking about tiling with porcelain planks. should the prep be plywood with staggered joins (perhaps made of 2 layers glued with staggered joins) nailed to floorboards and flex glued to concrete then de-coupling something layer and then the tiles. perhaps no more ply is better? any ideas or recommendations on materials/make-up?

 

[Dan]

You'll need to treat those areas as two separate areas and use an expansion joint / gap between them.

I'd still use a decoupling mat on both sides.

Don't nail to floorboards. You'll need to screw every 150mm with suitable screws that wont rust. If there are no timber joints under where you're screwing, you'll need to put some in.

It's quite the floor that. Not an easy job to do. How experienced are you? It really might be worth getting a professional tiler in. They could save you money on the job by getting all the gear at trade price and perhaps splitting the discount with you down the middle. As so many products are required for that type of floor setup - it may work out the discount covers their labour costs.

Some other similar threads:-

• Advice on herringbone pattern across old kitchen timber floor and new concrete extension floor - https://www.tilersforums.com/threads/advice-on-herringbone-pattern-across-old-kitchen-timber-floor-and-new-concrete-extension-floor.100023/
• Tilling over different floors (membrane/cement boards) + other questions... - https://www.tilersforums.com/threads/tilling-over-different-floors-membrane-cement-boards-other-questions.99971/
• 50/50 Floorboards Concrete room. Not level! - https://www.tilersforums.com/threads/50-50-floorboards-concrete-room-not-level.97970/post-974669
• 2 different sub floors problem! - https://www.tilersforums.com/threads/2-different-sub-floors-problem.95978/post-971928
• Levelling ground floor [repost] - https://www.tilersforums.com/threads/levelling-ground-floor-repost.88212/

Run a forum search for "Concrete Wood Floor" and you'll get dozens of existing threads. Feel free to reply to them, there's no date cut off, and people who contributed to those threads may still be around and be able to help.

Thanks for posting here at TilersForums.com

 

[christone]

You'll need to treat those areas as two separate areas and use an expansion joint / gap between them.

I'd still use a decoupling mat on both sides.

Don't nail to floorboards. You'll need to screw every 150mm with suitable screws that wont rust. If there are no timber joints under where you're screwing, you'll need to put some in.

It's quite the floor that. Not an easy job to do. How experienced are you? It really might be worth getting a professional tiler in. They could save you money on the job by getting all the gear at trade price and perhaps splitting the discount with you down the middle. As so many products are required for that type of floor setup - it may work out the discount covers their labour costs.

Some other similar threads:-

• Advice on herringbone pattern across old kitchen timber floor and new concrete extension floor - https://www.tilersforums.com/threads/advice-on-herringbone-pattern-across-old-kitchen-timber-floor-and-new-concrete-extension-floor.100023/
• Tilling over different floors (membrane/cement boards) + other questions... - https://www.tilersforums.com/threads/tilling-over-different-floors-membrane-cement-boards-other-questions.99971/
• 50/50 Floorboards Concrete room. Not level! - https://www.tilersforums.com/threads/50-50-floorboards-concrete-room-not-level.97970/post-974669
• 2 different sub floors problem! - https://www.tilersforums.com/threads/2-different-sub-floors-problem.95978/post-971928
• Levelling ground floor [repost] - https://www.tilersforums.com/threads/levelling-ground-floor-repost.88212/

Run a forum search for "Concrete Wood Floor" and you'll get dozens of existing threads. Feel free to reply to them, there's no date cut off, and people who contributed to those threads may still be around and be able to help.

Thanks for posting here at TilersForums.com

Hi Dan
Cheers for the input.
I hear what you say about treating the 2 areas separately with an expansion gap, that would solve potential cracking between them but I really don’t want the look of the expansion joint (at one point the wooden floor juts into the concrete in the outline of the old bay window so would look really apparent).
It is going to be a large job for me but I’m up for the challenge (not to mention having to level a dip in the concrete before getting started). I’ve tiled a few bathrooms before so I’m happy with the tiling part of the job.

 

[Dave]

Hi Dan
Cheers for the input.
I hear what you say about treating the 2 areas separately with an expansion gap, that would solve potential cracking between them but I really don’t want the look of the expansion joint (at one point the wooden floor juts into the concrete in the outline of the old bay window so would look really apparent).
It is going to be a large job for me but I’m up for the challenge (not to mention having to level a dip in the concrete before getting started). I’ve tiled a few bathrooms before so I’m happy with the tiling part of the job.

Can you post a pic of your floor areas please.

 

[christone]

Attached is a sketch of the area

 

[Dave]

Is the timber section heated as well. ?

 

[christone]

Is the timber section heated as well. ?

Hi Dave, the wooden floor section doesn’t have underfloor heating but there are wall radiators in those areas.

 

[Dan]

Tiling over wood and concrete

An expansion joint can look like a tile grout joint, doesn't have to be a huge line down it. You can get actual expansion thingies from the likes of Schluter (www.Shluter.co.uk) an the likes.

You can even get silicones to match grout colours (Mapei) and use that.

You'd just need to make sure the expansion joint went through all products. So a break in them all in the same place.

Those two floors are going to have totally different lateral expansion and retraction rates.

And they're quite big areas so the risk is greater if it fails.

 

[Dave]

Hi Dave, the wooden floor section doesn’t have underfloor heating but there are wall radiators in those areas.

Ok. Which way are you laying the planks ?

I’ve just done one with 2 heated zones and incorporated an expansion joint as a feature as suggested by the customer/builder.

The problem you have is the different rates of expansion between the two substrates and the point of deflection where Timber meets Screed.

 

[Dan]

Ok. Which way are you laying the planks ?

I’ve just done one with 2 heated zones and incorporated an expansion joint as a feature as suggested by the customer/builder.

The problem you have is the different rates of expansion between the two substrates and the point of deflection where Timber meets Screed.

That's a really nice floor that is mate.

 

[Dave]

That's a really nice floor that is mate.

Nice innit 😁

 

[christone]

Tiling over wood and concrete

An expansion joint can look like a tile grout joint, doesn't have to be a huge line down it. You can get actual expansion thingies from the likes of Schluter (www.Shluter.co.uk) an the likes.

You can even get silicones to match grout colours (Mapei) and use that.

You'd just need to make sure the expansion joint went through all products. So a break in them all in the same place.

Those two floors are going to have totally different lateral expansion and retraction rates.

And they're quite big areas so the risk is greater if it fails.

That's a really nice floor that is mate.

 

[christone]

I’m beginning to think that perhaps porcelain tiles might not be the material to go for (I like the durability and look but I don’t like the necessary expansion joints). If I chose vinyl planks instead would there be no problem about expansion?

 

[Dave]

I’m beginning to think that perhaps porcelain tiles might not be the material to go for (I like the durability and look but I don’t like the necessary expansion joints). If I chose vinyl planks instead would there be no problem about expansion?

If you use LVT , then as long as there isn’t too much deflection at the transition then it will be fine as it’s a loose lay covering

 

[christone]

If you use LVT , then as long as there isn’t too much deflection at the transition then it will be fine as it’s a loose lay covering

For the LVT option I take it just a base of plywood is ok with the ply screwed to the wooden floorboards and flex glued to concrete