Formplyfa or similar better material that can withstand being outdoors?

[Suhagg]

Planning to make a cover for a hot tub, and for the finishing surface, I was thinking of some form of gray/brown smooth nice surface. Waterproof and good lifespan.

Is there any affordable 120x240 board I can use for this that withstands moisture and being outdoors? The formply I’ve used for other things seems to have a tendency to swell and crack where it has been cut.

I'm thinking of this one.
https://www.byggmax.se/skivmaterial/byggskivor/plywood-och-osb/formplywood-p1004

 

[vectrex]

Wood-based boards will not last very long if you are going to have it lying down. Minerit maybe?

 

[bryggstun]

You can seal processed surfaces. Don't know how this works in practice.

There are plastic sheets used for, among other things, animal stalls. (walls in stalls and other uses.)
Ask at places where agricultural supplies are sold.
Maybe also possible to order in regular hardware stores.

I don't know what the sheets are called, but they are quite common. The ones we have are green.

 

[Suhagg]

Good tips.

 

[findus42]

Formply from the lumber yard is not waterproof. It's junk that falls apart faster than OSB. To get a board that lasts, you need durkplywood. Or filmed birch plywood. I've had one as a lid on my trailer since 1999.
Spångbergs in Högdalen or perhaps Holms trä can help you. Durkplywood is available in larger sizes than 1220 x 2444.

Regards / Findus

 

[Suhagg]

Formplyfa from the lumberyard is not waterproof. It's junk that falls apart faster than OSB. To get a board that holds up, you need durkplywood. Or filmed birch plywood. I've had one as a cover on my trailer since 1999. Spångbergs in Högdalen, or maybe Holms trä, can help you. Durkplywood is available in larger formats than 1220 x 2444.

Regards / Findus

2000kr for a board of 120x240. I need 2 It's becoming a bit too expensive for me.

 

[pelpet]

Build a lid out of painted råspont.

 

[Suhagg]

The wood takes a huge beating. -20 outside and then I fire up and it steams and is humid.
I think it needs to be something more durable and not as alive as regular wood. I think it's going to crack apart.

 

[bryggstun]

Those kinds of boards you place as platforms on trailers then. They have to withstand most things.

Ask where they sell and/or repair trailers.

 

[pelpet]

It's called Flakplyfa.

 

[corre]

The more organized hardware stores carry Marinplywood, which is much more durable. More similar to flakplyfa.

 

[Traume]

I think råspont, as someone mentioned, is the best option, cheap and easy to build with, and doesn't blow off as easily. If you then need to make a new one in 4-5 years, it's not a major cost.

 

[Traume]

I myself used a regular construction plywood for ours, (was supposed to be temporary haha) but it's still there. (yeah, maybe it's been 15 years, moved with us from the previous house which we sold 11 years ago) It works but it's not pretty.