Exposing Steel beam

[baker332]

Hi all,

About to have a knock through and wondering if I wanted to keep the steels exposed, can this be painted with fire-resistant paint afterward, as a retrofit? Or should this be done before the beam is put up?

Also, if I'd like to expose/keep the brick how do I find a work around for the padstones? Use a steel shim on a brick?

Thanks

 

[George_engineer]

Best painted before but can be applied afterwards. It will be an intumescent paint.

Depends on the loading - you can usually replace a padstone with 3 courses engineering bricks laid with M12 mortar. A steel plate may work, or even just brick if it is strong enough and the loads aren't too high. You'll need to speak to an engineer really.

 

[jks7492]

Its called intumescent paint. Yes you can apply it after the beam is installed - if the beam was pre-painted then likely the paint would need touching up anyway as no doubt the paint would be damaged in some way during transportation, lifting, installing any bolts etc..

 

[baker332]

Thing is not all of the beam will be exposed, so the top where the brick is seated and one of the side, would that matter?

 

[tony1851]

Also, if I'd like to expose/keep the brick how do I find a work around for the padstones? Use a steel shim on a brick?

Thanks

If you expose the brickwork, not only does it look naff and very 1970s, but it also holds the dirt and dust.

 

[freddiemercurystwin]

Intumescent paint works by when there is a fire the intumescent paint expands to create a 50mm thick insulation barrier around the steel and it is this thickness that provides the fire resistance. If the paint cannot expand to it's designed thickness it will not work as intended in the event of a fire.

Technically any areas where the paint would be ineffective because it cannot expand (such as the top of the beam because it's supporting a floor) would need to be adjacent to non combustible materials eg blockwork or concrete (rather than a timber floor). In theory the plasterboard ceiling could be designed so that it achieves a continuous fire proof lining but that would be down to Building Control to approve and for you to demonstrate what had been built will comply.

That said, presumably we're only talking about a domestic extension here rather than say a block of flats so the risks are less, and your BCO may be OK with such a solution.

 

[baker332]

If you expose the brickwork, not only does it look naff and very 1970s, but it also holds the dirt and dust.

You think exposed brick looks naff? Interesting, I thought people liked it, hence some asking for brick slips. You hold a valid point on the dirst/dust, however I live in a newish build (20 yrs old) and thought it may add a nice feature.

 

[baker332]

Intumescent paint works by when there is a fire the intumescent paint expands to create a 50mm thick insulation barrier around the steel and it is this thickness that provides the fire resistance. If the paint cannot expand to it's designed thickness it will not work as intended in the event of a fire.

Technically any areas where the paint would be ineffective because it cannot expand (such as the top of the beam because it's supporting a floor) would need to be adjacent to non combustible materials eg blockwork or concrete (rather than a timber floor). In theory the plasterboard ceiling could be designed so that it achieves a continuous fire proof lining but that would be down to Building Control to approve and for you to demonstrate what had been built will comply.

That said, presumably we're only talking about a domestic extension here rather than say a block of flats so the risks are less, and your BCO may be OK with such a solution.

I had no idea about the characteristics, thanks for providing detailed info really helpful.

 

[mikeey84]

live in a newish build (20 yrs old)

Are you sure you won't be exposing block work rather than bricks?

 

[noseall]

Hi all,

About to have a knock through and wondering if I wanted to keep the steels exposed, can this be painted with fire-resistant paint afterward, as a retrofit? Or should this be done before the beam is put up?

Also, if I'd like to expose/keep the brick how do I find a work around for the padstones? Use a steel shim on a brick?

Thanks

Intumescent paints require hoop jumps such as certification from the manu' before sign off. Even then, there were strict rules. We decided long ago that it was simpler to box them in.

 

[baker332]

Are you sure you won't be exposing block work rather than bricks?

Red Brick! What you think worth it or not?

Intumescent paints require hoop jumps such as certification from the manu' before sign off. Even then, there were strict rules. We decided long ago that it was simpler to box them in.

What does hoop jumps require?

 

[mikeey84]

I think exposed brick can work, but usually I like it in period houses. Not sure it would work in a modern house so much, but I'm no interior designer

 

[freddiemercurystwin]

He means the hoops by which you may well need to jump through to get it past Building Control, the specification needs careful consideration, as does how the beam meets the ceiling detailing and where it sits on the walls at the end, you'll likely need to provide the data sheets and test certification for the chosen product, you need to determine the thickness of the paint required (depends on the size of the beam actually this is quite simple) absolutely meticulous cleaning of the beam (degreasing etc) beforehand and application of the paint is essential, careful coordination between all parties is essential here so everyone knows where their responsibilities start and stop. Then when your Building Control officer asks how will the paint be maintained and checked and repaired as necessary over the anticipated life of the building how will you answer that? Long after you've moved out no one will give a hoot about it.

Then again your Building Control officer may be quite blasé about the whole thing and not care about any of that ....

 

[noseall]

He means the hoops by which you may well need to jump through to get it past Building Control, the specification needs careful consideration, as does how the beam meets the ceiling detailing and where it sits on the walls at the end, you'll likely need to provide the data sheets and test certification for the chosen product, you need to determine the thickness of the paint required (depends on the size of the beam actually this is quite simple) absolutely meticulous cleaning of the beam (degreasing etc) beforehand and application of the paint is essential, careful coordination between all parties is essential here so everyone knows where their responsibilities start and stop. Then when your Building Control officer asks how will the paint be maintained and checked and repaired as necessary over the anticipated life of the building how will you answer that? Long after you've moved out no one will give a hoot about it.

^^^^^^^^
Wot he said

What does hoop jumps require?

 

[baker332]

He means the hoops by which you may well need to jump through to get it past Building Control, the specification needs careful consideration, as does how the beam meets the ceiling detailing and where it sits on the walls at the end, you'll likely need to provide the data sheets and test certification for the chosen product, you need to determine the thickness of the paint required (depends on the size of the beam actually this is quite simple) absolutely meticulous cleaning of the beam (degreasing etc) beforehand and application of the paint is essential, careful coordination between all parties is essential here so everyone knows where their responsibilities start and stop. Then when your Building Control officer asks how will the paint be maintained and checked and repaired as necessary over the anticipated life of the building how will you answer that? Long after you've moved out no one will give a hoot about it.

Then again your Building Control officer may be quite blasé about the whole thing and not care about any of that ....

Thanks guys, I think if it's done well it looks great but might not be worth the extra hassle.

This was the look I was going for..