[drbabs]

Recently I have seen two homes with slate tiles for exterior wainscot.
Frankly, it looked really good.
why is this not used more often? real and fake stone products are common on exteriors. slate is relatively common on roofs- why not exterior walls?

 

[oh'mike]

It's a style that is currently popular---remember the sand stone from the 60s?

Just wait,tie dyed shirts and bell bottoms will be back!

 

[drbabs]

besides style though. this stuff runs 2-4 bucks a foot where manufactured stone and brick veneers run 4-10.

is adhesion an issue?
this house is 4 years old and looks ok so far

 

[Ron6519]

Many slate products will not work well in a wet environment. They are soft and delaminate.
You need to pick a slate, up to the job.

 

[stadry]

ron's exactly right - slate is a product of sedimentation & resultant compression,,, as a result, its susceptible to delamination from freezing intrusive water ( don't even ask if there's a product to prevent this - there isn't ! :no: )

slate is also comparatively soft & has little compression OR tension strength.

 

[Tom Struble]

they better stop using it for roofs then:wink:

 

[stadry]

slate roofs ( known as 100yr roofs ) use a quality product far better than what's commonly purchased today,,, IF buyers knew quality slate, they wouldn't buy the **** now being sold at apron/vest stores,,, you'd rarely find that quality spec'd in any architectural building - residential OR commercial,,, its largely disappeared from roofs due to replacement by less expensive materials,,, roofing slates are also installed with 1/3rd reveal - NOT a full exposure as shown by the op

 

[Anti-wingnut]

ron's exactly right - slate is a product of sedimentation & resultant compression

Absolutely untrue. Slate is the resultant product of metamorphism ( read heating and pressure combined) of a fine grained sediment. The result is a entirely new rock from the protolith, with an entirely different crystal structure of its constituents.

It is commonly composed of mica and micaeous minerals, elongate amphiboles such as hornblende, quartz and feldspar. It is the middle rock of the metamorphic continuum of progressive metamorphism of a shale parent, shale - phyllite - slate - schist. The mineralogy would not be susceptible to absorption of water, and the structure would also tend to shed water.

It would be possible for water to enter cracks and interstices in the rock, and if this was followed by freezing, the spalling and other modes of failure could result.

The statement by the OP at ContractorTalk of the presence of natural oils in slate is also completely false. Metamorphism would evaporate any and all volatiles contained in the matrix.

Anti-Wingnut
Construction Management and Geologist
BS Geol and Graduate Studies

 

[drbabs]

ron's exactly right - slate is a product of sedimentation & resultant compression,,, as a result, its susceptible to delamination from freezing intrusive water ( don't even ask if there's a product to prevent this - there isn't ! :no: )

slate is also comparatively soft & has little compression OR tension strength.

ok, we have 20 year old slate on the floors of a hunting cabin lots of hot anc cold . no problems there at all. so cheap slate can go on floors, but for roofs and exterior stuff there must be a higher grade of slate. "frost resistant" i think is the term for outdoor applications. I am curious about the sealing of a slate product as I have seen slate on shower ceiling applications.

how about normal ceramic or porcelain floor tiles? High compressive and tensile strength, no lamination issues. Totally water fast. How would this do for an exterior wainscot when installed properly?

 

[stadry]

ok - ok - OK, wing ! ! ! so i sits corrected :laughing: a walk thru any cemetery will reveal delaminating slate monuments which, i theorize, would not occur IF slate were more dense or homogenous,,, it is precisely why granite is chosen for monuments over slate, marble, concrete, common stone, etc,,, i don't recall if slate has a ' grain ' but granite does

no scientific data but do rely on experience in our family's cemetery monument biz ( over 100yrs ) + repairs to many slate/marble monuments,,, IF we were to choose slate, my choice would be pa's pen arglyll or vermont verde,,, enjoy your day ! :thumbup: thanks for the post, too !

 

[Ron6519]

how about normal ceramic or porcelain floor tiles? High compressive and tensile strength, no lamination issues. Totally water fast. How would this do for an exterior wainscot when installed properly?

How often do you see ceramic tiles on exterior walls? I've seen them now and again and thought, "Why would you do that?" I would think you would need something a little more visually diverse and significant. Veneer stone over tiles would be a more substantial choice.

 

[drbabs]

Absolutely untrue. Slate is the resultant product of metamorphism ( read heating and pressure combined) of a fine grained sediment. The result is a entirely new rock from the protolith, with an entirely different crystal structure of its constituents.

It is commonly composed of mica and micaeous minerals, elongate amphiboles such as hornblende, quartz and feldspar. It is the middle rock of the metamorphic continuum of progressive metamorphism of a shale parent, shale - phyllite - slate - schist. The mineralogy would not be susceptible to absorption of water, and the structure would also tend to shed water.

It would be possible for water to enter cracks and interstices in the rock, and if this was followed by freezing, the spalling and other modes of failure could result.

The statement by the OP at ContractorTalk of the presence of natural oils in slate is also completely false. Metamorphism would evaporate any and all volatiles contained in the matrix.

Anti-Wingnut
Construction Management and Geologist
BS Geol and Graduate Studies

BLINK BLINK......



wow. I asked for a cheese snack and you baked me a wedding cake!
ok, so in laymans terms. what is you opinion about installing slate on exterior walls, assuming the proper underlayment and proper flashing etc.

thanks for everyones opinions here.

 

[Ron6519]

BLINK BLINK......



wow. I asked for a cheese snack and you baked me a wedding cake!
ok, so in laymans terms. what is you opinion about installing slate on exterior walls, assuming the proper underlayment and proper flashing etc.

thanks for everyones opinions here.

It would need to be a higher grade of slate, not the soft earth tone stuff sold ay the big box stores. Espesially if you're in a freeze zone.

 

[Anti-wingnut]

Exterior slate wall tiles are a common finish detail on commercial jobs. As was stated by others, there are grades which are perfectly suitable for exterior use. The big stores sell by price point. Seek out a reputable contractor and architect if needed to ensure that the section of wall is built correctly, all the way back to the ply wood and rain screen if needed

 

[dharring]

how do you make sure slate stick to the wall . I am installing slate on my front prouch and i need to put some on bottom of the wall below the floor . what should i do make shure it dosn't fall off thanks
Dave