which plasterboard and how to enclose steel beams

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mundungus

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Hi All,

I'm currently in the thick of it, with an extension to our house. The brick work is pretty much done, and roof going up right now. Money is running out rapidly, so I'll be doing any boarding up myself, possibly the skimming too.

I've been reading loads about the different types of board, and their purposes and listening to general advice from the builder. But really not sure how it all fits with our extension.

Firstly, our downstairs is largely open plan now. Kitchen dining room and living room. So if I need moisture board for the kitchen, does that mean I need it throughout, as its open plan with the other rooms?

Secondly, there are a number of steel beams to box in. The builder said that it has to be two layers of plasterboard over any beams for building regs (in case of fire). Is that true?

Is that still true if I use red board (fire board)? and if all edges need to be taped up, what kind of tape? Is it any different to the mesh tape that you'd generally use for joins between boards?

I'd really appreciate you folk setting me straight, and dispelling any myths or nonsense I might be reading.

Many thanks,
Keith
 
No need for moisture board in a kitchen.
Beams should be double fire boarded with staggered joints. They should be jointed with paper tape and easifil (or similar) but unless the building inspector is stood behind you most of us would just skim as normal.
 
The double normal plasterboard he refers to is the equivalent to 1 fireline plasterboard I normally put csl wood noggings in steel (which is a skill in itself) leave slightly proud to pop a couple of screws from underneath and on front..when money starts to run dry on this kind of project id advise try and save money on the kitchen appliances and units etc to pay a plasterer to do and finish it well.it's the most important part of the build
Best of luck
 
Follow the spec on your drawings, they will tell you how steels should be boarded. On my house I'm doing now spec was layer of 12.5mm fireboard then layer of normal 12.5mm plasterboard.
 
stuart23 said:
Follow the spec on your drawings, they will tell you how steels should be boarded. On my house I'm doing now spec was layer of 12.5mm fireboard then layer of normal 12.5mm plasterboard.
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You correct different areas seem to have different spec..one fireline has 30 minutes fire resistance if I remember rightly and so does 2 standard plasterboard maybe they spec more on yours as Mrs doesn't like to be disturbed ... Even if house is on FIRE !
 
The spec here is single
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My drawings don’t specify how to box in the beams. I could ask the architect I suppose. I guess he just expects it to be to building regs standard. I’ve been reading the building regs documents online, but they’re not terribly clear on what type of board will suffice, nor how many layers.

So if I understand you guys correctly I can either use two layers of normal grey plasterboard, or one layer of red? Also, I can use normal grey board everywhere else even though some of it is a kitchen?

Back to the boxing in; the beams are mostly C shaped, so I can put noggins in the C, but some of the boxing needs to be on the flat side, i.e. the back of the C. Do I just glue the board to it (gripfill or something similar) or am I supposed to build a wooden frame around it somehow?

With the noggins, do these just get glued in too? The steel is quite thick, I can’t imagine I’m supposed to drill through it, to screw through the steel into the noggins.
 
mundungus said:
My drawings don’t specify how to box in the beams. I could ask the architect I suppose. I guess he just expects it to be to building regs standard. I’ve been reading the building regs documents online, but they’re not terribly clear on what type of board will suffice, nor how many layers.

So if I understand you guys correctly I can either use two layers of normal grey plasterboard, or one layer of red? Also, I can use normal grey board everywhere else even though some of it is a kitchen?

Back to the boxing in; the beams are mostly C shaped, so I can put noggins in the C, but some of the boxing needs to be on the flat side, i.e. the back of the C. Do I just glue the board to it (gripfill or something similar) or am I supposed to build a wooden frame around it somehow?

With the noggins, do these just get glued in too? The steel is quite thick, I can’t imagine I’m supposed to drill through it, to screw through the steel into the noggins.
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Upload a load of pictures for everyone then can give best advice
 
Building regs drawing should read , what hour protection
Easiest to just use fire line boards


I would usually let a full timber into steel well & fix
Then slate lath top & bottom
Using bottom lath to fix
Your soffit board to ..
 
Hello mate

I was talking to an Architect about this very thing yesterday - see the attached files, 1 shows the Knauf Encasement Clip, which then holds the encasement C Channel, then the other shows how to put them together onto a column and then screw fix the 2 layers of firepanel boards

Good luck

Richard Lord
Knauf
 

Attachments

  • Metal Sections Knauf Fixing Clips.pdf
    29.4 KB · Views: 2,409
  • Encasement Detail.png
    Encasement Detail.png
    48.2 KB · Views: 6,309
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Measures inside of 'C' and add a couple of MM on. Cut cls to that size then hammer home. For the bottom part just use a grab adhesive, no point over complicating things.
 
mundungus said:
So would they expect you to drill holes through the steel to put screws into the noggins?

Some parts of the steels must be 8mm to 10mm thick.
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Usually you leave the noggins in the side proud or blast a few hilti nails into a batten in the base then screw as normal
 
mundungus said:
I will try to get some pictures up a bit later.
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If you look at @stuart23 photo they are the easiest way to do them .. Cut the cls timbers to the exact or just a few mm more and bash them into steel and they will then be tight fit try and leave them sticking out slightly say 4/5 mm and if the board is scored on pink side you can then put screws in side a bit of adesive on steel underneath (to grab underside of board) then fold board under the bottom and round the other side at the same time,screws in noggs on other side ,slight tap on underside ,then pop a few screws into all nogs that stick out from underneath to secure,jobs a good un.
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:wtf:....Notice join on the fire board to the sound block blue (bg) boards ? Yes I know there is quite a big difference in the level of existing joist and the new steel the BUILDER put in, not a big problem for this PLASTERER to over come I simply had to float/ blend the two together to give the illusion that it was not put in right.
Very common discrepancy I come across, needless to say saved the BUILDER and the customer coming to blows :burlas:
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stuart23 said:
View attachment 12861 View attachment 12862 Measures inside of 'C' and add a couple of MM on. Cut cls to that size then hammer home. For the bottom part just use a grab adhesive, no point over complicating things.
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Try next time to fix 25x25 angle on the first board , prior fixing to the timber. The second skin will cover it completely and you will have solid base for the one n the bottom. Works perfect :).
Can't advise plasterman on this, he is using one skin only:rolleyes:
 
we dont feck about with noggins or knauf c clips or any other long winded method.

fit the soffit of the beam first. cut the board to the overall required size, apply a thin coat of plasterboard adhesive all over the back of the board . slap the board into position, no need for props. leave to set.

cut the boards for the side to be fitted inside the soffit board. apply dry wall adhesive to the soffit board and the top flange of the rsj, fit side board.
 
malc said:
we dont feck about with noggins or knauf c clips or any other long winded method.

fit the soffit of the beam first. cut the board to the overall required size, apply a thin coat of plasterboard adhesive all over the back of the board . slap the board into position, no need for props. leave to set.

cut the boards for the side to be fitted inside the soffit board. apply dry wall adhesive to the soffit board and the top flange of the rsj, fit side board.
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Building inspectors don't pass it like that anymore though Malc , they want to see screw fixing in at least nog or batten, last one told me it's because the screw will not melt before the adhesive would come away from the steel , his words not mine , don't shoot the messenger.
:frio:
:popcorn:
Don't worry @mundungus we will get to a conclusion in a bit.. Any pictures yet?
 
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