Plant room wall covering - will ply suffice?

[sean1933]

Following a slight move around to accommodate a larger downstairs WC (dont ask) we now sort of have 2 separate plant rooms - a HVAC/wet room, and an electric/loxone cupboard.

House is block/brick cavity walls with a mix of block and stud internal walls.

When I fitted the UFH manifold I stuck a full sheet of 12mm ply to the block wall to ease fitting. The top half will be used for supply Hot/Cold water manifolds.

The plant room and cupboard are both mainly timber stud. As they are 'service rooms' my intention was to just fit ply straight to the studs and leave it at that. Ceiling would probably be plasterboarded but I haven't given it much thought - given the amount of HVAC ducting (2 units) I'd even considered not fitting any.

 

We are due to have the internal 3 phase consumer unit installed on Friday and the cupboard is currently just ply'd floor to ceiling.

I thought this was fine but having read a few other threads I'm confused if this is acceptable or does it need covering with plasterboard/skim to give some fire protection (or paint with expensive intumescent paint).

If I need to cover it, will there also be an issue with the ply stuck to the block wall? I must say something that appears so trivial is causing me a headache.

thanks in advance.

Edited December 6, 2022 by sean1933

[ProDave]

BC might insist you paint it with a fire retardant paint.

[pilgrim]

I asked the same question to my building control inspector recently about my small utility room / pantry and he sent me the attached page in reply, and said

"Your plywood will meet D-s3, d2, but any standard higher than that will require expensive paint treatments, or overcladding with plasterboard.

 

Looking at the table above, if your utility room has a floor area under 4m2, plywood will be fine, but if your utility floor area is more than that you will only be able to untreated ply cladding up to an area equivalent to half the floor area. So as an example, if your utility room has a floor area of say 10m2 then only a maximum 5m2 area of untreated ply would be allowed."

 

Hopefully that will be the same for you.

[sean1933]

On 07/12/2022 at 22:33, pilgrim said:

I asked the same question to my building control inspector recently about my small utility room / pantry and he sent me the attached page in reply, and said

"Your plywood will meet D-s3, d2, but any standard higher than that will require expensive paint treatments, or overcladding with plasterboard.

 

Looking at the table above, if your utility room has a floor area under 4m2, plywood will be fine, but if your utility floor area is more than that you will only be able to untreated ply cladding up to an area equivalent to half the floor area. So as an example, if your utility room has a floor area of say 10m2 then only a maximum 5m2 area of untreated ply would be allowed."

 

Hopefully that will be the same for you.

 

Only just seen this - thanks very much it covers the problem perfectly, I'll have to plasterboard some of the walls annoyingly but heyho! 😄