Shuttering Ply v OSB

[JDW]

The sales guy at my local yard has suggested I use 18mm shuttering ply for my workshop lid because the price of OSB had gone through the, ahem, roof (get it before the price goes up next week he said...better than osb he said...).

Now I know Shuttering ply is also known as roofing ply but opinions seem split on this soni thought I'd ask for some more opinions and see if I can make a decision.

OSB3 is £53 a sheet and the ply is £31

I'm topping with breathable membrane and poly felt.


Thanks

Jim

 

[robgul]

I'd go for the ply - my bike shed is ply with some felt and has been just fine for years.

 

[MARK.B.]

18mm ply for £31 a bargain in this period of price hikes and shortages, I would use ply not just because its cheaper but because I find it much easier to work with

 

[Jameshow]

You'll think us when your hefting shuttering ply over OSB!

I would always go plywood over OSB. Stronger and nicer to work with.

Does OSB use for glue???

Cheers James

 

[JobandKnock]

Shuttering ply is generally softwood ply with large veneer repairs in it. The structural plywood we use on roofs is normally hardwood ply, albeit cheap Chinese stuff these days

Above: Softwood shuttering plywood
Below:Hardwood roofing (structural) plywood

 

[artie]

I abandoned shuttering/sheathing/good one side ply years ago in favour of osb for the sake of consistency.

 

[JDW]

Thanks chaps, appreciated. Differing views as I expected. Both solutions work is the bottom line I guess. I had a look at the ply in the yard and its tidy, very flat and smooth. Right, I'm buying it now before I start thinking again

Cheers, Jim

 

[robgul]

18mm ply for £31 a bargain in this period of price hikes and shortages, I would use ply not just because its cheaper but because I find it much easier to work with

More likely 12mm if it's shuttering ply?

 

[JobandKnock]

Depends on the shuttering. Most of what our brickes have been using to cast padstones has been 18mm - 12mm would require too much framing to stiffen it. For smaller flights of stairs cast in situ and other larger stuff that's what I have used in the past, too, but you can also get 22 and 25mm shuttering ply (at least in phenolic). Not a shuttering joiner, but at one time we were all taught how to do basic shuttering as part of the trade and the odd time or two over the years I have to do it, or sometimes oversee it. Not a job I enjoy TBH

 

[JDW]

Its 18mm

 

[artie]

I abandoned shuttering/sheathing/good one side ply years ago in favour of osb for the sake of consistency.

Another thing I remember from long ago sheathing ply if left uncovered in out houses would soak up damp and damp spores would sometimes appear.
Not a problem with osb.

 

[hairy]

I seem to remember Peri the formwork company will do 40mm shuttering ply if you ask

 

[Phil Pascoe]

Another thing I remember from long ago sheathing ply if left uncovered in out houses would soak up damp and damp spores would sometimes appear.
Not a problem with osb.

The OSB I've used has been exactly the same. I've an OSB clad cupboard in the bathroom that I've been putting off tiling for several weeks that's going black.

 

[JobandKnock]

@hairy that 40mm ply must carry some weight! Most of the big formwork I've seen in recent years is either steel "pans" or bespoke welded steel stuff

Bit OTT for a shed roof, though

 

[JobandKnock]

The OSB I've used has been exactly the same. I've an OSB clad cupboard in the bathroom that I've been putting off tiling for several weeks that's goung black.

Is it OSB3, though? And are you sure that isn't caused by condensation due to lack of ventilation? Common cause of black mould in houses

 

[sawdustandwax]

Given the price rises in sheet goods it's makes metal roofing make more sense as £ per sq m.

 

[artie]

Given the price rises in sheet goods it's makes metal roofing make more sense as £ per sq m.

Metal roof is increasing in price too.

 

[Phil Pascoe]

Is it OSB3, though? And are you sure thst isn't caused by condensation due to lack of ventilation?

Steamy when the bath is run, but that's it. The window's been open since the job was done. Regular 95% - 98% humidty probably doesn't help though.

 

[artie]

Regular 95% - 98% humidty probably doesn't help though.

Since I got the bathroom rh down below 60, most of the time.
There's been no mould.