Understanding RSJ fireproofing/compartments

Joined
23 Sep 2012
Messages
121
Reaction score
3
Location
Buckinghamshire
Country
United Kingdom
Good morning experts,

Just looking for some advice to help with some post flood renovations that we are doing. We are creating a new ensuite in an existing garage conversion that has a bedroom above. Structure isn't changing, just gutted it because of an abysmal (but bc signed off) insulation job and moving around the layout.

We have an RSJ that spans where the new ensuite will be located and remaining garage next door that previously only had a single layer of skimmed 12.5mm standard plasterboard. We are now getting to the point of starting to seal everything back up and I'm just trying to understand the requirements for fire protection.

Does the requirement for fire protection of the RSJ apply to just the immediate 'underside' of the RSJ itself, or to the entirety of the compartment that it is within? The first thought was to do 15mm fireboard in the ensuite itself but then standard 12.5mm board in the rest of the space, which is separated by stud wall, which has a top plate running it's entire length.

So, in theory, the room immediately below the steel has 15mm fireboard protection, but the connected cavity in the adjoining room does not (but could, just hate working with the 15mm stuff!). Is this ok, or should the entire compartment in which the RSJ sits be to the same protected standard? Hopefully the attached sketch shows what I mean with pink line denoting fireboard, grey standard board?

Thanks in advance.
 

Attachments

  • RSJ.png
    RSJ.png
    11.1 KB · Views: 49
Sponsored Links
If the beam is exposed to a room, the exposed sides need protecting.

If the beam is within a floor or ceiling void, no additional/specific protection is required as the void would have it's own 30 minute protection from the floor ceiling layer.
 

DIYnot Local

Staff member

If you need to find a tradesperson to get your job done, please try our local search below, or if you are doing it yourself you can find suppliers local to you.

Select the supplier or trade you require, enter your location to begin your search.


Are you a trade or supplier? You can create your listing free at DIYnot Local

 
Sponsored Links
Back
Top