Tiling an Attic conversion - Tile Advice

[IvanP]

We want to tile the entire attic conversion with a 600 by 600 8mm Porcelain 8mm tile. The Attic is on 6 inch rafters and the largest floor is 4370 by 4775. Some tilers I've talked to have expressed doubts about tiling an attic like this, they say it will be impossible to do without continual problems due to movement, even with backing boards. Does anybody have any advice or any similar experience?

 

[Dan]

How far apart are the rafters? And is there deflection (bounce) in the floor already?

Can you not add proper joists to the supporting walls below? Is the floor covered already or something?

 

[IvanP]

How far apart are the rafters? And is there deflection (bounce) in the floor already?

Can you not add proper joists to the supporting walls below? Is the floor covered already or something?

Hi Dan,

The joists are 400 apart and the floor is already covered in Chipboard. I'm just worried about movement after. When you ask about adding proper joists, what do you mean?

 

[Dan]

Well, can you not pull up the chipboard and stick 12" joists onto the load bearing walls below? Next to the existing joists?

Effectively making a new solid suspended floor throughout. Is their enough height to do that?

I'm not a tiler by the way so wait for somebody who's done this before to reply.

But that floor doesn't sound solid enough.

Have you called Mapei Adhesive technical help line to see what they recommend in your situation?

Mapei UK | Adhesives, Sealants, Chemical Products for Building

Mapei UK Official site. The leading company in the building industry, with over 80 years of experience in adhesives, sealants & chemical products.

www.mapei.com

Have you got a floorplan you can upload to the forum? How many rooms are there to take into account?

 

[IvanP]

Well, can you not pull up the chipboard and stick 12" joists onto the load bearing walls below? Next to the existing joists?

Effectively making a new solid suspended floor throughout. Is their enough height to do that?

I'm not a tiler by the way so wait for somebody who's done this before to reply.

But that floor doesn't sound solid enough.

Have you called Mapei Adhesive technical help line to see what they recommend in your situation?

Mapei UK | Adhesives, Sealants, Chemical Products for Building

Mapei UK Official site. The leading company in the building industry, with over 80 years of experience in adhesives, sealants & chemical products.

www.mapei.com

Have you got a floorplan you can upload to the forum? How many rooms are there to take into account?

Thanks for the clarification Dan. It is something I could check, I think there is enough Height to allow it. I've attached the floor plan of the whole space. I'll try the technical helpline you suggested, thanks!

 

[Dumbo]

Have you had an architect involved in this.
It may pay to spend a few quid and get a structural engineer to survey it and follow his recommendations on joist build up and loadings ,obviously telling him you intend to tile, not for his tiling recomedations but so he knows what extra weight you are putting in