Slate or Metal Profile

[JaneF]

Any thoughts on Spanish slate vs metal profile roofing for a green oak clad barn conversion? 

[Cpd]

By the time you batten and then counter batten I think either will work fine, not quite sure which one will hide any movement better……. If it was me and I had the budget ( I don’t) I would go slate but that’s going to be soooooo much more expensive than a tin roof. I now just use tin as it’s so cheap and quick and is great quality these days. 

[IanR]

Traditional Barn or modern shed?

 

Are you in an area where slate is typical on an agricultural (timber framed) barn?  I'm more used to seeing clay tiles. 

 

How about standing seam metal roof? I'm not so keen on the visible fixings of metal profile on a conversion, plus the cut ends will corrode, unless you go for some more exotic that steel.

[saveasteading]

2 hours ago, IanR said:

How about standing seam metal roof? I'm not so keen on the visible fixings of metal profile on a conversion, plus the cut ends will corrode, unless you go for some more exotic that steel.

 

That is only partly true.

here is more info than you probably want. 

 

The fact of it being steel is not the issue, as it is cut in such a way that the ends remain galvanised protected.

 

Cut end peel can be a problem with plastisol, unless you pay more for the upgraded material, or apply a lacquer.

It is not a problem with other coating  finishes like pvdf or the rarer superpolyester.

 

There are many grades of quality in both the metal and the finishes.

Buy the best and there is little concern.

 

As to standing seam. The main advantage is of course that no screws are visible, along with less chance of leaks as there are fewer penetrations.

The same applies with composite panels.

The disadvantages are that any damage in future is very difficult to replace.

If you cut holes into the panel, then closing off is awkward and ugly, and the leaks benefit is reduced. This applies especially  on very big roofs.

And cost. I never had a client, spending their own money, who chose to go standing seam. ie architects specified it but were not aware of, our didn't consider, the cost.

I reckoned that one screw in 500 (at 10/m2) might need tightening after which there would not be a problem, and that was on 10 degree slopes.

 

If near the sea or pollution then additional checks are necessary for material and coating, esp re seagulls. 

[Patrick]

5 hours ago, JaneF said:

Any thoughts on Spanish slate vs metal profile roofing for a green oak clad barn conversion? 

How about metal shingles?

[JaneF]

13 hours ago, saveasteading said:

 

That is only partly true.

here is more info than you probably want. 

 

The fact of it being steel is not the issue, as it is cut in such a way that the ends remain galvanised protected.

 

Cut end peel can be a problem with plastisol, unless you pay more for the upgraded material, or apply a lacquer.

It is not a problem with other coating  finishes like pvdf or the rarer superpolyester.

 

There are many grades of quality in both the metal and the finishes.

Buy the best and there is little concern.

 

As to standing seam. The main advantage is of course that no screws are visible, along with less chance of leaks as there are fewer penetrations.

The same applies with composite panels.

The disadvantages are that any damage in future is very difficult to replace.

If you cut holes into the panel, then closing off is awkward and ugly, and the leaks benefit is reduced. This applies especially  on very big roofs.

And cost. I never had a client, spending their own money, who chose to go standing seam. ie architects specified it but were not aware of, our didn't consider, the cost.

I reckoned that one screw in 500 (at 10/m2) might need tightening after which there would not be a problem, and that was on 10 degree slopes.

 

If near the sea or pollution then additional checks are necessary for material and coating, esp re seagulls. 

When you say cut holes, for velux fir example?

[IanR]

52 minutes ago, JaneF said:

When you say cut holes, for velux fir example?

 

When the roof is first installed they'll be no reason to "cut holes in panels", can only assume the poster is referring to retrofitting something to the roof in the future.

 

For a standing seam roof: roof lights, soil vent pipes etc. would either have flashings created from the same material (if the material used is ductile enough ie. zinc, copper, aluminium) or may need a separate material to seal up to the penetrations.

Standing seam is a good option for agricultural/industrial conversions. I've got 500m² of aluminium standing seam on mine and it looks correct in an agricultural environment, is suitably light weight for the roof structure of what was previously an agricultural building. Lots of material choices to suit the budget.

[saveasteading]

9 hours ago, JaneF said:

When you say cut holes, for velux fir example?

Yes, but also flues, vent pipes.

 

If the cladding is predominantly flat, and the opening happens to come through the flat part, then flashing is easy enough but the sheet is weak at that point.

if there are multiple crowns to cut through then a mini gutter is needed at the top.

It is difficult. so tricky that, aesthetics ignored, it is common to add another flat sheet all the way to the ridge.

 

With pre-planning the velux can have the appropriate flashing kit, the cladding is cut on site to suit and all is well.

 

I am surprised it isn't recognised as being tricky in housing (my main experience is large steel buildings) unless......perhaps there is always another waterproof layer below, the vapour barrier, which is catching the leaks and carrying them away.

 

Traditional roofing of slates or tiles (which drip onto each other) , then flashings and tape, then vcl then sarking provides a lot of opportunity to catch drips and deal with them. Steel onto steel is very exposed.

 

Many penetrations in steel are sealed with silicon, and it can be a problem. It works long enough for payments to be made,  but fails in a few years.

 

I know..I have been on many a roof to fix the bodges, by reforming flashings, using proper seals, and with very special silicon tape that stays flexible.

 

I remain utterly in favour of metal roofing.  Just make sure it is a good spec, and fitted by experts, as IanR will have done. Agricultural cladding is half the price, and good enough for cattle and hay.