how do plasterboard sloping ceiling - metal studwork?

[Helen888]

We are converting loft space into a bedroom. The  dwarf walls are

only about a foot high so the sloping ceilings come almost to the

floor. Just wondering how on earth to attach plasterboard to the inside

of the roof - does studwork on a sloping roof have to be wood - I'v'e

seen metal rail type things  for  building studwork but not

sure if they are just for dividing walls etc. or whether it would be

strong enough. Grateful for any advice at all on plasterboarding

sloping ceilings!

[Smiley]

I would suggest that you need an architect/surveyor to make that assesment. It may well be that the rafters are big enough to take the weight of the boards but it all depends on size/age/etc. You need to insulate between but still leave enough gap to allow free air movement. Do you have this? These are only questions that a site survey can answer. Sorry to be vague but it's not a simple question to answer.

[Deimos]

I have still to do my attic - but had (yet another) architect round a few days ago. There are different types of rail for horizontal ceilings ("suspended" design) and stud walls. However, I forgot to ask about those at the same inclination as the roof - i.e. the roofing type or stud wall type. I will probably ask at the builders merchants when I go to start purchasing the stuff (but if somebody else here knows that would be great).

Ian

[Monika]

In our house renovation the plasterboarders used the metal rail system in the roof as well. One of our "loft rooms" sounds very similar to yours. They put airflex insulation (the thin foil type) and then nailed the metal rails to the rafters and beams and inset the plasterboard still showing some of the beams. This is not very technical, sorry! I try and enclose a photo but it might not work.

[Val_2]

Plasterboard should always be attached to the roof via the metal tracking as roofs move a great deal especially old properties. This system also allows for insulation to  fitted andheld in place as well as any electric cables. Invest in a proper screwdriver especially for plasterboarding screws, saves a great deal of time and watch the tracking, use proper cutters as it is very sharp.

[Iceni]

We had a similar issue and dealt with it as follows

Airflex type insulation rolled out sideways and stapled to rafters - thus leaving air gap below tiles - and joined where necessary with wide silver tape.

Metal rails screwed to purlins, roof beam etc thus ensuring air gap between insulation and plasterboard.  Lots of purlins, A-Frame and roof beam still visible. Enduit/joint tape have cracked in a couple of places proving that something has moved - but not seriously.

HTH

John

not

[Just Katie]

Nothing wrong with fixing the plasterboards directly to the roof rafters as long as you use condensed kingspan or similar insulation.

[Just Katie]

[quote user="Val_2"]Plasterboard should always be attached to the roof via the metal tracking as roofs move a great deal especially old properties. This system also allows for insulation to  fitted andheld in place as well as any electric cables. Invest in a proper screwdriver especially for plasterboarding screws, saves a great deal of time and watch the tracking, use proper cutters as it is very sharp.[/quote]

Val, how are you independently fixing the metal tracking to the roof?  If the roof is always moving, surely the tracking will too when fixed. Do you think that that is the problem Iceni has encountered?

[Deimos]

Visited somewhere that knows yesterday(builders merchants) and the guy spent some time going through it all with me. The same rails are used for ceilings and walls EXCEPT that for the ceilings (or roof attachments) they are not screwed directly to the roof but hung from special metallic strips. These strips have ends shaped to hold the rail U upwards (i.e. the way up you should hand a horse shoe). these strips are available is short lengths (few cm) to quite long (longest where I went was 40 cm) with a range of sizes between. These allow the roof to move a bit whilst the plasterboard stays put (and thus does not crack). Looks dead easy (and actually looks much easier than screwing the rails directly to the wood roof).

Ian

[Bob T]

I have used the metal rails on ceilings and walles. On ceilings the suspenders allow you to get a flat even plasterboard ceiling whe the rafters are not level. Not trying to teach anyone to suck eggs, but it goes like this:

Fasten one hanger in the corner of a room. With a string and spirit level fasten another hanger in another corner on the same beam. Do this for all four corners. Once the corners are set and screwed to the beams, they should all be level. Then fasten the sting along one beam from hanger to hanger and at about 50 or 60 cm intervals fix more hangers.. Do the same on the beam at the opposite side of the room. When these two rows are in place you can use the string to fasten the hangers to every beam in between. You can then clip the railing onto the hangers. At this point mark the walls where the rails are so that you know where to fix the plasterboard to. Srew the plasterboard up using proper screws (come in different lengths) make sure that the countersink on the screw goes flush with the surface but does not break it by screwing too far in. You can then tape the joints and fill the screw heads and you should have a level ceiling.

Don't forget to lay any cables for when the rails are attached but before the plasterboard goes on. If you have a heavy light to attach then put a one foot square of plywood above the plasterboard at that point to spread the load.

If you are fitting to an area that may get damp, ie bathroom, then use the green plasterboard as it is moisture resistant.

Hope this helps.

[Deimos]

Very useful - many thanks Bob T

Couple of questions:

1) On the parts where the roof is inclined (i.e. not vertical walls, nor horizontal ceilings but where there is a part parallel with the roof, should the rails run across the rafters on in line with the rafters. I had assumed across the rafters to spread the load and stop the rail slipping under gravity. However, if along, should the hangers be vertical or perpendicular to the roof. If vertical they rail will not align decently for the plasterboard to be fixed to and if perpendicular then they will have a sideways load - which is not ideal as the ones I saw were strips of metal - or are there special sorts of hangers for inclined fitting ?

2) Does one do all the framing forst (ceiling and walls, the start to fix the plasterboard. If so, does one fit the ceiling or walls first (or does it make little difference) ?

3) Cables. Can/does the heavy duty double insulated cable or must you use the 3 individual cored in gaine) or "both" (run the double insulated stuff through gaine. I suppose I am more includes to use gaine as there are no space limitations.

4) At the builders merchants I noticed there are a wide range of rail width. Clearly ceiling hangers are designed for a specific width. However, Is there any reason why one should not use wider rails for walls, thus allowing more rockwool for sound insulation and providing a more rigid wall (there are reasons why I do not want to put two sheets of plasterboard on each wall).

Many thanks

Ian

[jxedwards]

Ian,

I have just finished railwork and plasterplate in my loft only the decorating left.

Looks like Bob has you on the right track so I will not interfere or meddle in words.

I can send you some pictures which may help explain Bob's excellent narrative

Send me a PM if you want some pics

 

Regards

 

John

[Bob T]

I would do the ceiling first, then the sloping wall. If the sloping beams are almost flat then I would be tempted to screw the rails directly to the beams with wooden packers to keep it all flat. I would use the rails horizontally. By finishing the ceiling first you can cut the plasterboard at the sloping beams to make finishing the joint easier.

As for cables, I use the tree idividual cables in the flexi conduit, this makes life easier as the cables can be too long and there is no problem shoving them behind the plasterboard.

If you use hangers on the sloping beams then the rails must be horizontal and the flat face of the rail must br flat against the plasterboard. If you were to try and fit them vertically then they could slide down the hangers with the weight of the board.

[Helen888]

brilliant - thanks for all your help. I just wondered, I've some of

that reflective insultation but want to layer it with some normal 

fibre glass insulation that i might as well use up. I've been told that

the silver stuff needs to go in first (closest to roof) with fibre

glass next before plasterboard - is this correct?

[Just Katie]

Hangers on to the rafters.  Sorry Val, I did not know about that one.  Genuinly sorry.

[Millwheel]

Hello John,

I have an attic to 'fit out' as my next project. I would be very grateful if you could send me some pictures. I hope with your pics & the 'words of wisdom'  from the others on the forum I should be able to figure out  what I need to do.

 

Many thanks,

Nigel. 

[Cassis]

Hope these help.  I've got plenty more!

[IMG]http://i68.photobucket.com/albums/i26/cassiscassis/house/grenier4.jpg[/IMG]

[IMG]http://i68.photobucket.com/albums/i26/cassiscassis/house/PICT0001-1.jpg[/IMG]

[IMG]http://i68.photobucket.com/albums/i26/cassiscassis/house/PICT0019-1.jpg[/IMG]

[IMG]http://i68.photobucket.com/albums/i26/cassiscassis/house/PICT0035-2.jpg[/IMG]

[IMG]http://i68.photobucket.com/albums/i26/cassiscassis/house/PICT0031.jpg[/IMG]