I’m on holiday so struggling to look this up and argue about it.

 

My architect wants us to have all the steel in our timber frame sent away to be sprayed with intumescent paint.

 

I cannot find the regs at the moment but it seems totally over the top in a two storey house.

 

He argues that just putting it behind fire rated board is not enough.

 

It would be a massive pain and expensive to do during frame erection.

 

Scottish regs apply. Any thoughts?

I have had the same row with an architect.  I don't understand how a ceiling can be 1 hour fire resistant yet not suitable to protect a steel beam.  BG were not much help and we reach an impasse where the architect specified intumescent paint and I will have a fight on site with the Building Inspector.

You can get it sprayed on site 

All of the commercial buildings I work on are protected by pb or sprayed 

Spraying isn’t cheap 

The only 2 I’ve worked on in Scotland were both sprayed on site.

 

1 hour ago, AliG said:

I’m on holiday so struggling to look this up and argue about it.

 

My architect wants us to have all the steel in our timber frame sent away to be sprayed with intumescent paint.

 

I cannot find the regs at the moment but it seems totally over the top in a two storey house.

 

He argues that just putting it behind fire rated board is not enough.

 

It would be a massive pain and expensive to do during frame erection.

 

Scottish regs apply. Any thoughts?

Odd specification and can you be more specific on what items or sections we are talking about.

if it’s truss assemble steelwork (flitch, king/queen post or heal plates etc) then intumescent paint would prevent good close fitting and strength.

if it’s a truss tie bar or support beams etc then I can see the benefit of fire protection … sort of.

spraying is rarely done off site/pre erection due to the delicate nature of the intumescent coating.

The paint I’ve seen used is also water based so needs protection if it’s likely to get wet!

22 minutes ago, TonyT said:

The paint I’ve seen used is also water based so needs protection if it’s likely to get wet!

 

Typically rust bleeding through and the paint is soft and yellowing.  Also for the paint to work you need to leave a space around it for it to expand.  I hate the stuff.

Thanks guys.

 

I will post drawings in a bit, in the US at the moment.

 

Basically a few posts in the walls and beams holding up upper floors.

 

The argument seems to be that putting them behind plasterboard is not enough protection, but I am willing to hear other views.

 

I told the architect I want to speak to BC and see what they say as it is going to cost the best part of 5k plus be a big hassle.

8 hours ago, AliG said:

Thanks guys.

 

I will post drawings in a bit, in the US at the moment.

 

Basically a few posts in the walls and beams holding up upper floors.

 

The argument seems to be that putting them behind plasterboard is not enough protection, but I am willing to hear other views.

 

I told the architect I want to speak to BC and see what they say as it is going to cost the best part of 5k plus be a big hassle.

We have quite a few steels and it was either paint or put behind plasterboard. 

A timber frame holds up the upper floors and plasterboard is ok to protect the timber.

I just spoke to the architect and he says they spoke to building control this morning and they are insistent the steel is either directly encased or painted. Putting it behind plasterboard is not acceptable.

 

MBC seem to have agreed to paint it though. Which saves a lot of hassle.

So, somehow 60 minutes of protection was specified and when I checked the regs I reckoned it was 30 minutes.

 

The 30 minutes seems to be correct which reduces the cost of the intumescent painting.

 

However, tomorrow I will be asking the question if the insistence on paint and not plasterboard protection was due to the incorrect 60 minute requirement.