Tiling onto OSB board

[genoveg]

Cab anyone advise if it is acceptable to tile directly onto OSB board for wall tiles. I have done in the past but wonder if this will hold up in longterm. Board is secured and has minimal if no deflection.

Any help appreciated

 

[DHTiling]

Simple answer is NO!!.....

 

[wetdec]

For those unsure about OSB ...............not mine

Oriented strand board (OSB) is made of layers of thin rectangular strips of wood (from shredded trees) that are compressed and bonded together with a binder. The grain of the strips for each layer is oriented perpendicular to one another, similar to plywood. The layers are built up with the external layers aligned in the panel direction and internal layers randomly positioned. It is then placed in a thermal press. Although, OSB sounds better than plywood there are some disadvantages. When the OSB panel is exposed to water in excess of its rating the water is absorbs at its edges (due to the inherent porosity of its edges), and swells a little more that plywood. When Plywood panels absorb water, they swell wherever the water is absorbed. OSB will stay swollen while plywood will shrink back to its original thickness, because the compaction force is lessened.



Hence, OSB is rarely used for an underlayment


tiler

..

 

[Alberta Stone]

That's right.
Don't use it.

 

[genoveg]

Thks for replies. Was pretty sure that it would need to be covered somehow.

Problem is little room has been left to clad on say some cement backer board as shower mixer has been set quite tight with little tolerance to allow for anymore depth except spread n tiles.

Would it be worth considering using a sheet waterproofing product, have seen something in Topps that may help?? To confirm, it is only the back wall of 1000 x 800 shower, 1 side has tile backer and other is masonry plastered wall.

Thks

G

 

[beanz]

When the OSB panel is exposed to water in excess of its rating the water is absorbs at its edges (due to the inherent porosity of its edges), and swells a little more that plywood.

If you primed it on back n sides, like you would with Ply, wouldn't this negate the problem of water penetration!?! Just curious, as it's a damn site cheaper than Ply, and i know all the local Flat Roofers now use OSB, as they say it's better than Ply!?!?!

 

[Spud]

If you primed it on back n sides, like you would with Ply, wouldn't this negate the problem of water penetration!?! Just curious, as it's a damn site cheaper than Ply, and i know all the local Flat Roofers now use OSB, as they say it's better than Ply!?!?!

is it worth the risk ? I dont think so, why take a chance when there are so many good cement backer boards available

 

[beanz]

Yeah i just found another old thread, that makes me think that it definitely isn't worth the risk hehe! 😉

 

[2Balls]

Hi, Replace the Osb with something more suitable!:8:2Balls