Top and bottom plates for a low timber framed wall

[Arron]

Hi. As mentioned in a previous post, I need to make a low timber framed wall 900mm high and 2500mm long. It is actually an extension of a wall on our balcony, so needs to be made strong and safe. It will be fixed at either end to existing vertical posts, one timber and one steel.

The problem is that it is curved through a 1200mm radius. I need to make top and bottom plates to fit that radius?


Possibly relevant: 90mm x 35mm timber will be used. Steel strapping. Hardiflex cladding. Rendered. Probably will have a cap flashing made by Stratco. Needs to match existing 12mtrs of same. The dimension of the chord (shortcut across the curve) is actually about 2300mm

One idea I had was to use structural ply cut to shape and laminated together to give 45mm thickness or thereabouts.

Another idea was to buy 190x45 timber and cut to shape, fixed end to end with scarf joints, and sister pieces below to reinforce.

Both time consuming and not cheap - did I mention this is a temporary solution - probably 2 year lifespan.

Does anyone else have any other suggestions?

Cheers
Arron

[Camelot]

I have made curved walls using ply, you don't really need to build them up to 45mm, just cut one to the radios and use it as a template to make another 4 (use a router with bearing to follow the shape)

You will now have 5 shaped ply pieces, use one for your soul plate and the other for you header, cut enough studs to give you 300 centres, put your end 2 studs in first, then cut the 3 remaining ply radios to a length long enough to act as noggins to maintain your 300 centres (the inside radios dimension if using 35mm stud would be 265mm)

You could use a offcut of your radios ply as a template to put against the back fence of your chop saw, this would give you a concave shape to reference against when cutting you radios ply noggins.

Then starting from one end fix a ply noggin (to the soul & header radios ply) tight up against your end stud, this will give you the location for your next stud, repeat the process until you get to the other end, you should have enough noggins left to do a centre row (just pin them in place) Get a hose pipe on your Hardiflex and let it get really wet, to allow you to bend it to the radios.

Hope that helps

[rwbuild]

Use ply for plates as previous poster said or nearest plasterboard supplier and get stud and curved track
Steel Stud & Track Wall Framing System | Rondo

[Arron]

Use ply for plates as previous poster said or nearest plasterboard supplier and get stud and curved track
Steel Stud & Track Wall Framing System | Rondo

Thanks for the reply.

The curved track wall framing system is interesting but obviously it’s flexible when you buy it so how do you make it rigid ?

Cheers

[sneakynuts]

Thanks for the reply.

The curved track wall framing system is interesting but obviously it’s flexible when you buy it so how do you make it rigid ?

Cheers

You can sheet it the same as you would a timber framed wall

[rwbuild]

Being captive between 2 end supports the hardiflex sheeting both sides will automatically lock the plates to the 1200 radius

[Camelot]

With it being external you may need to take into account wind loads and the dry wall curved systems are designed for internal applications, Maxiframe is Rondo's external wall system and I am not sure they offer it curved.

[Arron]

Thanks for the responses.

So I’m basically relying on the cladding and any fixings to the floor (remember it’s only 900mm high so not fixed to the ceiling members) to maintain a rigid curve? That concerns me a bit.

Anyway, I’ve just been up to measure the space again and I was wrong in my original post - the chord is only 2000mm - so I think I could easily get a sufficient number of laminations out of one standard sheet of plywood. Therefore if I go plywood I will be sticking to what I know best which is probably smart as there is a safety angle here.

Another question. One side will be fixed to a 90mm galvanised post, and the other side to a 90mm hardwood post. I’ll probably just screw into the hardwood post, but what is the best way to fix to the gal post??

I feel I should be trying to minimise the holes made in the gal post - should I really be worried about that ??

Cheers
Arron

[Camelot]

Thanks for the responses.

So I’m basically relying on the cladding and any fixings to the floor (remember it’s only 900mm high so not fixed to the ceiling members) to maintain a rigid curve? That concerns me a bit.

Anyway, I’ve just been up to measure the space again and I was wrong in my original post - the chord is only 2000mm - so I think I could easily get a sufficient number of laminations out of one standard sheet of plywood. Therefore if I go plywood I will be sticking to what I know best which is probably smart as there is a safety angle here.


Another question. One side will be fixed to a 90mm galvanised post, and the other side to a 90mm hardwood post. I’ll probably just screw into the hardwood post, but what is the best way to fix to the gal post??

I feel I should be trying to minimise the holes made in the gal post - should I really be worried about that ??

Cheers
Arron

So you are really building a dwarf wall only fixed at both ends, then increase your laminations at the top header, also within the length of the wall (if you can) where ever possible keeping to the constraints of the radios let vertical studs go down below your floor zone (assuming joist construction) and bolt them to the side of your joists (you can also add blocking between joists to achieve the right position and then fix the vertical studs to the side of the blocking.

I would self tap to the steel post it will not effect it structurally, the wall will also benefit in rigidity because it is curved.

[Arron]

So you are really building a dwarf wall only fixed at both ends, then increase your laminations at the top header, also within the length of the wall (if you can) where ever possible keeping to the constraints of the radios let vertical studs go down below your floor zone (assuming joist construction) and bolt them to the side of your joists (you can also add blocking between joists to achieve the right position and then fix the vertical studs to the side of the blocking.

I would self tap to the steel post it will not effect it structurally, the wall will also benefit in rigidity because it is curved.

The floor of the balcony is already finished - scyon flooring / waterproofing / screed / more waterproofing / tiles.
I don’t want to cut through that. I thought being only 2 meters long it was adequate to simply fix at both ends and make sure the construction is rigid.

This was meant to be curved frameless glass with top railing. After many problems we got the curved glass made ($750 per panel), but no one seems to be capable of making the top railing. I had a steel rolling specialist company attempt it without success (an expensive exercise nonetheless). The low wall is simply my attempt to kick the problem down the road a bit and deal with it in a year or two.

[Camelot]

You can have curved glass without a top rail the rail can be fixed to the side of the glass, either top or side, just fix the glass panels in place and make a template for some steel fabricator to make you what you need, I don't see why it should be so difficult for anyone in the trade, you would then save the abortive cost of this temporary work.

I would also suggest once the panels are in place why not make a ply laminated top rail (say 4no. 18mm ply) with a grove in the bottom the same thickness as the glass and then slot in place fixed at either end until your steel one it fabricated.

[Arron]

You can have curved glass without a top rail the rail can be fixed to the side of the glass, either top or side, just fix the glass panels in place and make a template for some steel fabricator to make you what you need, I don't see why it should be so difficult for anyone in the trade, you would then save the abortive cost of this temporary work.

I did think of the solution you mentioned (an offset rail) but as I understand it I can’t now get holes drilled in the toughened glass. On Monday I will ring the glass manufacturers and verify that. If they can drill the holes then that solution is back on the agenda.

I would also suggest once the panels are in place why not make a ply laminated top rail (say 4no. 18mm ply) with a grove in the bottom the same thickness as the glass and then slot in place fixed at either end until your steel one it fabricated.

I think the problem there would be conformity to Australian standards. Further, if I go the route of the frameless glass I need to get it installed by the a pro installer, and get the appropriate certificates. We even need to present certificates for the spigots in this council area so I assume same with the handrail. Further, I can’t see any pro installers wanting risk their licenses on my homemade plywood solution. I am liaising with our certifier on this and I’m aware he isn’t going to let anything slide.

So I figured taking the glass panels back to Sydney to get the holes drilled, making a template, getting the offset rail made, getting an installer to install the glass panels and rail, and then removing it and reinstalling my final solution would be about the same amount of work as making a timber framed wall myself. I have bandsaw, high speed stroke sander, nail guns, ability to render, airless spraygun, plus plenty of leftover framing timber, render and paint. Therefore I don’t think the wall is a big or expensive job - and I won’t end up with holes in the glass.

If I go the timber framed wall route my main issue is I don’t know whether I will be required by standards to have intermediate fixings through bottom plate to deck. I assume not as it’s only 2 metres long and will be securely fixed at either end. I don’t want to do any balcony floor penetrations myself - although I’m OK with the pro installers doing them.

I’m still not convinced which way to go though and at this stage am just gathering information - so your comments are most welcome.

[Camelot]

Because you have a certifier involved it would probably be best to see if he will pass your dwarf wall construction method.

With the plywood top rail it could be made out of external grade ply and have say a 15mm round over bit to all 4 corners then paint it black and tell the installer and the certifier that is your finished rail (change it later), I don't believe there is anything in the code saying top rails can't be made out of wood.

I hope you planed where the stirrups would be located and a fixing provision was allowed for within your sub floor

[Arron]

I hope you planed where the stirrups would be located and a fixing provision was allowed for within your sub floor

No, we didn’t, but I have shown it to the installer who did the installation of the other 15 meters of glass and he says he will have no difficulty doing the remaining two. I didn’t ask for detail.

This has all come about because the original plan required massive aluminium vertical louvres in this area and along another 12 meter section of the balcony (both upstairs and down - there is a downstairs balcony as well). I ditched the louvres late in the project for a variety of reasons including reasonably valid complaints from the neighbours about blocking light to their living room and kitchen.

[Arron]

Went to a glass merchant today who said it’s impossible to drill holes in toughened glass - it’ll just explode.

So my options are narrowing.