Working with slate......

[JDLDIY]

Got a few jobs to do where I will need to 'bang in some slate'. Just wondered how the pro's cut it to size, anglegrinder? If necessary, how's best to split it if it's too thick also? I know this maybe an obvious question to some, but using the best technique from the off can't half save some time and hassle.
Cheers
JD

 

[DAZB]

The pro's would use a Slate Knife / Axe or Slate Cutters like these :

http://www.tooled-up.com/MicroCategory.asp?CID=12&SCID=134&MCID=700


Slate can easily be cut without tools by holding the sides with it lengthways in your hands ( so you are holding the long sides ) and breaking it over the corner of a wall , kerbstone , bench , labourer ! etc.
Alternatively you can cut it by placing it overhanging a flat surface and using a chopping action with the edge of a trowel but this may waste a good amount of the slate but if you are just using it for packing that may be a good thing.

 

[JDLDIY]

Thanks DAZB, I'd not seen those tools b4, don't think I'll be lashing out on one though, as you say it's fairly easy to break or cut.

Thing is though, given say a 5mm gap and slate 10mm thick, how is it thinned down?

 

[DAZB]

You don't thin it down you just pick up a thinner slate. As they are a random product you will get thick thin and in between so you should manage with any size gap.

 

[JDLDIY]

You don't thin it down you just pick up a thinner slate. As they are a random product you will get thick thin and in between so you should manage with any size gap.

Surely though as these tiles are produced for roofing purposes they must be sliced to a uniform thickness in the quarry (or during a post quarrying process)? I mean I know there will be a small difference in the shapes, contours and thicknesses being a natural product, but not too much surely?

 

[DAZB]

There can be as much as 20mm difference in extreme cases but it is quite common for variance of 5-10mm from one slate to the next. The art of a skilled roofer is to " coarse " out the roof which means grading the slates in terms of thickness and lay the thicker slates on the lower coarses and the thinner slates as you rise up the roof.

 

[JDLDIY]

The art of a skilled roofer is to " coarse " out the roof which means grading the slates in terms of thickness and lay the thicker slates on the lower coarses and the thinner slates as you rise up the roof.

Sounds like a nightmare!
So for pretty small gaps under joists etc, like 5mm I'm not going to be able to use slate really, so what then? I guess I could use lead?

 

[DAZB]

Slate will be fine for packing joists because it will tighten in against the timber and the brick . It is the standard method in the Building trade.

 

[pieman]

gotta be worth trying to split a few sheets, say with a bolster? If you don't need particularly big pieces, slate splits along the bed so easily. Maybe give the edge of the bolster a tickle on the grindstone if its blunt.

Or, use someone else's wood chisels