Wall framing and roof trusses

[Barry_White]

Hi Mr5point7

It is normal to install your gyprock with a horizontal joint and as skew says the filler would be better at the bottom because it means you wont have a tapered edge and will make it easier to fix your skirtings.

As far as the ceiling goes you are better using furring channel attached to the bottom of the trusses and you wont need in between ceiling joists. Furring channel will span up to 1200mm and you just run them at right angles to the trusses.

[elphingirl]

If you're using Gyprock, you'll notice that it has rebated edges to help conceal the joints. With a 300mm filler like you describe, at best only one edge of the filler will have this rebate, making concealment that much harder. Also, at any height between around 900mm and 2.4m height any dips or lumps in the joint (or plaster) will be readily noticed; that's where people look in day to day living. Having two joints there doubles the problem... :eek:

Personally, I'd be more inclined to put the filler at the bottom... so that even if the lack of a rebate makes a less than perfect joint it'll be less obvious. You'd be surprised how few people see what's at their feet.

Totally agree with this - having had to joint some of my own dodgy PB application. Avoid rebated-cut joins wherever possible - they are the absolute hardest - worse that cut-cut joins. Definitely avoid a joint at eye height - horizontal light from windows will make this joint really obvious.
It's a bugger of a job in any case.
Cheers
Justine

[boban]

Thanks for all the replies

I was thinking about installing the noggins from at 1350cts from the bottom plate and 1350cts down from the top plate. I wanted to install the plasterboard horizontally so i don't need to go up and down the ladder to do the 1st and final coats for the plaster.

I would have:

1350mm pb at the bottom
1350mm pb at the top
300mm pb in the middle (cut 1200mm wide pb into 4 sections)

This would mean I would have 2 joins of plaster pretty much in the middle of the wall (saves me using ladders doing the joins vertically)...

What do you think?

I was going to put the noggins all at the same level so all the plasterboard joins have a bit of 'meat' to hold on to... any thoughts?

So there is no such requirement from the BCA to have the noggins staggered?

Oh, the truss... looks like everyone is saying they are pretty easy to lift. I will let you know in a couple of weeks how I go. Unfortunately no crane to lift them in place. The extension is at the back and access to there is a via the 1m side path.

Thanks again.

1. As far as the noggins are concerned, they are not meant to provide support for plasterboard according to the literature I have read.

2. Plenty of big cranes if you really want one to get over your existing house, but really not necessary. 3 of us lifted my 12m trusses over my 2.7m frame. It wasn't easy but it didn't take too long.

3. For a 3.0m wall, it is best to use a 1200, 1200 and 600 sheet. The 600 is obviously cut from another 1200. You will have all the rebates you need and less wastage.

[echnidna]

3. For a 3.0m wall, it is best to use a 1200, 1200 and 600 sheet. The 600 is obviously cut from another 1200. You will have all the rebates you need and less wastage.

Thats the best way to do a 3metre wall.
It puts all the horizontal joins well below and well above normal eyeline so you don't notice any minor lumps and bumps in the join.

Using 1350 sheets with a 300 filler puts a horizontal join at 1650 so every minor imperfection in the join will stand out prominently.
If you must use 1350 sheets with a 300 filler, the filler needs to go up the top so none of the horizontal joins are at general eyeline height.

[KeepaTalk]

With 900 centers you obviously are going to have a tin roof. If it was my house I would have 600's, and it also makes it easier to climb around your roof for fixing batons etc.

And furring channel is the way to go you can get your ceiling perfectly level.

[mr5point7]

Thanks everyone... I always thought the noggins where there to aid with the plasteboard and the joins Yeah, to think about it - obviously that's what it's not for, rather for structural stability.

Yeah, I think I will go for 2 1200mm and a 600mm filler at the bottom. Thanks for the great advice

Yes, it will be a tin roof. The furring channels are a great solution!!! I will do this instead. However, leaves a problem that the existing ceiling and the new ceiling will be at different levels due to the furring channels to the new extension. Hmmm, one dilemma after another :confused:

BTW, can prefab roof trusses have a birdsmouth? My existing roof has a birdsmouth on the rafters... Surely the new trusses would need to have a birdsmouth so they sit exactly like the existing...

[Barry_White]

Thanks everyone... I always thought the noggins where there to aid with the plasteboard and the joins Yeah, to think about it - obviously that's what it's not for, rather for structural stability.

Yeah, I think I will go for 2 1200mm and a 600mm filler at the bottom. Thanks for the great advice

Yes, it will be a tin roof. The furring channels are a great solution!!! I will do this instead. However, leaves a problem that the existing ceiling and the new ceiling will be at different levels due to the furring channels to the new extension. Hmmm, one dilemma after another :confused:

BTW, can prefab roof trusses have a birdsmouth? My existing roof has a birdsmouth on the rafters... Surely the new trusses would need to have a birdsmouth so they sit exactly like the existing...

Prefabricated trusses don't have a birdsmouth because the truss sits on the bottom chord on top of the wall plate and usally with either a triple grip or has builders strapping over the top of the truss and down each side and fastened to the side of the wall plate and the wall stud.

The difference in the height of the ceilings wont be seen unless the ceiling is in one continuous plane. If it is separate rooms as I said it wont be seen.

[mr5point7]

Unfortunately, the ceilings will be continuous... so you will be able to see a difference in levels. Doesn't matter... It will have to do, otherwise I think I will use hanging beams and span some ceiling joists across to keep the ceiling level right through.

If my existing rafters have a birdsmouth, then my new prefab trusses will sit higher (top chord) then my existing roof... Looks like I have to get talk to my prefab person...

Any recommedations in Melbourne for roof trusses?

Thanks

[KeepaTalk]

When you put your external walls up you will have to put a ribbon plate on them. A ribbon plate is another piece of timber on top of your top plate.

This should take up the difference in your ceiling heights. Also the ribbon plate stops the bottom chord of the truss sitting on the internal walls, which will make the truss ineffective. The external walls are load bearing.

With the plaster not sure if putting your 600 piece at the bottom is the best because it puts your join at 1800, near enough eye level. So if your stopping up is a bit rough it will be quite apparent. I'd go with 1200 1200 600.

[kva]

13MM PLASTER CAN SPAN 600mm AS WELL AS 10mm CEILING PLASTERBOARD, OTHERWISE BATTENS AT 450mm FOR STD 10mm PLASTERBOARD.
IF THE TRUSS SPACING IS 600mm MAX. U CAN FIX THE PLASTERBOARD TO THE UNDERSIDE OF THESE.

[mr5point7]

When you put your external walls up you will have to put a ribbon plate on them. A ribbon plate is another piece of timber on top of your top plate.

This should take up the difference in your ceiling heights. Also the ribbon plate stops the bottom chord of the truss sitting on the internal walls, which will make the truss ineffective. The external walls are load bearing.

With the plaster not sure if putting your 600 piece at the bottom is the best because it puts your join at 1800, near enough eye level. So if your stopping up is a bit rough it will be quite apparent. I'd go with 1200 1200 600.

I was told the bottom chord sat directly on top of the top plate. They sit pretty much line ball with the vertical studs which are approx 3m high. I have no internal walls in my extension. It's the new kitchen area (basically a 7.3m wide and 5.6m deep room - no internal walls to this area; pretty much a big open space) and the trusses would effectively be sitting on the external walls? So would there be a need for a ribbon plate???

The trusses are currently being spaced at 900mm centres... I guess the extra costs in a couple of trusses wouldn't hurt if I went for 600mm centres. This would ultimately save me in getting hanging beams and extra ceiling joists... I think the extra costs per truss would be roughly $180 each truss.

[ptyltd]

Hooly Dooly…..That’s one big kitchen :eek: !!!

I recently did some trusses that were over a 6m span on my own so thought I would share how I stood them (although I had 2 large opening that allowed me to get the truss inside the extension so this may not suit). If you can get the truss into the middle (ish) of the extension you put one end up on the top plate (upside down – i.e with the apex pointing down), then using a ladder lift the other end up onto the top plate so the truss is hanging across the span - upside down. Next move the truss into position from the ground level which is easy to do with the truss hanging like this. I then positioned a long beam vertically in the middle of the span (braced to take the weight of the truss – I just used lots of clamps etc.) close to the truss but far enough away so when the truss is swung up it will lean on it at a slight angle (you also need room to swing so you work in one direction). Then using another long beam (I used some old studs nailed together) push the apex of the truss so the truss goes through the horizontal and then up to the right position leaning against the vertical post (Warning – this is obviously dangerous if you let the truss swing back down from a height so be careful). Once the truss is standing next to the vertical post, put up another vertical post on the other side at roughly the plumb position and you can then (with the help of the posts on each side) maneuver the truss into it true position before fixing at the ends. When gripped at both walls the trusses can stand unsupported but are pretty flexy up the top so when they are all standing you need to secure a batten across the top chords near the apex (making sure they are plumb) to stiffen them all up. This was probably the hardest part (for me anyway) due to the height you are working at. Mine were 900 crs so I had joists (which are floppy as at those spans) in between and to stiffen these up there were two wooden binders running across the top of the joists and trusses. <O</O
<O</O

All told it actually wasn’t that hard to do on my own because as a dead weigh the trusses are not that heavy just bloody awkward due to the size. If you had another helper you could still use this method as it is not that hard and whilst it was easy for me to get the truss into the staring position as I had 3m openings in one wall I am sure it wouldn’t be hard getting the truss over a wall. In relation to the difference in ceiling height you can need to look at the member sizes used in the existing roof and the extension and then you could use either different top plate heights for the extension or ceiling battens to bring the two ceiling to the same level.<O</O
<O</O

Anyway just thought I would share how I lifted my trusses as this was one of your original questions.<O</O

[mr5point7]

Bigger is better they say

I sorta understand where you are coming from. I will have a 3300mm opening for my bifolds so I guess I can enter through here with the trusses.

I am guess you mean the apex points in the middle of the room. You would lift the ends of the truss to be sitting on the top plates, meaning the bottom chord will be above me when i stand on the floor. Then you just 'flip' the truss over so it stands upright... I think this is what you were saying ptyltd. I like this idea.

Thanks

Yeah it looks as thought the existing rafters are 150mm (more so 120mm)... So the trusses won't need a birdsmouth.

To combat the ceiling levels, I will just order a few more trusses and space them at 600mm centres just like kva said... and directly sheet the underside of the bottom chords.

[ausdesign]

Generally the pitching point (top plate or ribbon plate) is determined on an extension by working the measurements down from the underside of the iron which with a 125mm birdsmouthed rafter is within 10mm of the original.
This keeps any valleys etc on the same plane.
But depending upon the original rafter size & the original fascia fixing location it is possible in some cases to 'tweak' the pitching point to enable plaster battens to be run under the bottom chord & line up the ceilings.