Thread: bi-fold doors

[quote;371928]
I realize that the doors won't exactly be smooth in their operation since I plan on not installing any bottom guide track, and with the doors folding flat against the outside wall, they will be inclined to chatter and jam when you initially attempt to close them, but if you're careful and you know exactly where to apply pressure then they should work alright in theory. I've got my fingers crossed anyway[/quote]
I would really consider a bottom track, there's going to be a lot of weight hanging from the top channel, even when shut. When opened, without support from the bottom, the doors will not stay upright/plumb.

Just wondering how you're going to have the doors running on a top track and folding flat against the wall? Not really possible without having some curves on the end of your top track, as far as I can figure out. Also, do you know what species your KD hardwood will be and how stable it is? Some timbers will continue to move with atmospheric changes, even years after being dried. Not good when used for joinery, especially if containing glass.

Mick

Originally Posted by rowie

I would really consider a bottom track, there's going to be a lot of weight hanging from the top channel, even when shut. When opened, without support from the bottom, the doors will not stay upright/plumb.

When shut the flush bolts will hold the doors in position, besides there is no tendency for the doors to wind. The track width is 63mm and the door thickness is 45mm so the centre of the door will be 4mm (clearance) + 22.5mm from the face of the jamb, = 26.5mm total. The track will be hard against the jamb in the closed position so the centre of the track will be 31.5mm from the face of the jamb. This means that I'll have to offset the carriage by only 5mm from the centreline of the door which is 'nothing' really. There should be no tendency for the doors to wind.
In the open position it is a different matter. the weight of the opening leaf (third leaf) will tend to twist the second leaf inwards at the bottom towards the first leaf (jamb leaf) but by careful placement of the track, I can ensure that there is only minimal clearance between the leaves when open (say 4mm). The second leaf will rest against the first leaf at the bottom, and have minimal clearance at the top.
I don't think that this minimal amount of wind will affect anything.

Originally Posted by journeyman Mick

Just wondering how you're going to have the doors running on a top track and folding flat against the wall?

I plan to install the track in two segments, one for each set of three doors. As I've stated in the post above, the track will be hard against the jamb at the closed position. It will then travel at an angle so that when the carriage reaches the fully open position, the centre of the track will be 45mm (jamb rebate depth) plus 10mm (first leaf clearance) plus 45mm (first leaf thickness) plus 4mm (second leaf clearance) plus 22.5mm (half of second leaf) plus 5mm (track offset from door centreline) which gives a total of 131.5mm from the face of the rebate in the open position. In the closed position it will be 31.5mm from the face of the rebate.
The doors should travel to the open position quite easily, however closing them is another matter. When closing them initially, the doors have to swing a large distance in relation to the distance that the carriage moves along the track. This would tend to make the carriage chatter and jam, however if you're careful, and you know where to apply pressure, then they should work allright in theory anyway.
This is one reason that I don't want to install a guide track at the bottom. Besides being ugly to start with, it would have to be at an angle that corresponds with the top track, making it doubly ugly.
I have polished floorboards on the inside, then a 20mm step down to decking boards. The doors will close hard against a mohair strip on the edge of the internal floorboards.

Originally Posted by journeyman Mick

Also, do you know what species your KD hardwood will be and how stable it is? Some timbers will continue to move with atmospheric changes, even years after being dried. Not good when used for joinery, especially if containing glass.

Mick

I don't know what species it is, and yes this is a concern. They will be closed for most of the time though so most of them will be restrained at the top and bottom. Of course the two central leaves will only have a single lock in the middle so they will be free to twist and wind, and I may have to install bolts on the top and bottom.
I'm sourcing the timber from Barrenjoey Timbers
240X45 @ $34.25/metre
140X45 @ $14.95/metre
90X45 @ $8.65/metre
If anyone knows of anywhere cheaper in Sydney let me know.

Another concern is sagging in the head. I've installed a 300X65 Hyspan LVL which has already sagged 5mm even before the ceiling has been gyprocked. Once the weight of the ceiling and these big hardwood doors goes on it I expect it to sag a bit more. There's 20mm adjustment in the carriages but it's no good having the track travel uphill too much because of head sag, so I'll install the track with 20mm packers which will give me something to play with if I have to adjust the track up to make it level.

Pawnhead,
still not sure about the "flat against the wall" bit. Does the opening run into a wall at 90deg at both ends? If so, yes, the doors will fold flat against the wall. If the opening is bounded either end by a wall that's parrallel to the opening (which is what I assumed) then there's no way that the doors will fold flat.

If the former, then there's no need to run your track at an angle, if the latter, well the geometry just won't let you do it.

Mick

Hi Pawnhead,
Sounds like a big job cutting all those M&T's in hardwood by hand!
Have you thought about WRC instead of red (or white) cedar...I don't know the price comparisons, but its light, chisels well, good for doors and handles the weather OK. For dressed stuff, you're looking at: 140x38 $22.39/m and 92x32 $14.93/m, & you may be able to get custom sizes.

Good luck with it.

Originally Posted by journeyman Mick

If the opening is bounded either end by a wall that's parrallel to the opening (which is what I assumed) then there's no way that the doors will fold flat.

If the former, then there's no need to run your track at an angle, if the latter, well the geometry just won't let you do it.

Mick

Yes, it's the latter, and I beg to differ. I don't think there's anything in the geometry that would prevent their operation in theory, however as I've said, you'd have to be very careful when initially closing them. If I put even more of an angle in the track (say an extra 50mm, making it 181.5mm from the rebate face), then it would make the closing operation smoother, however it also means that the doors wouldn't stack as flat against the wall, and I'd loose the support of having the second leaf leaning against the first leaf in the fully opened position. This would tend to stress the second leaf into a winding position because of the fact that it is supporting the weight of the third leaf. I could overcome this by drilling an extra hole in the outside decking for the flush bolt in the second leaf, so I could bolt the door in the open position. This would eliminate any torsional stress, but I'll try setting it up with tight tolerences first and see how difficult they are to operate.

Originally Posted by Andy Mac

Hi Pawnhead,
Sounds like a big job cutting all those M&T's in hardwood by hand!

You're not wrong there, but if I can save four grand then it will be worth it. As I've said, I've got time on my hands.

Originally Posted by Andy Mac

Have you thought about WRC instead of red (or white) cedar...I don't know the price comparisons, but its light, chisels well, good for doors and handles the weather OK. For dressed stuff, you're looking at: 140x38 $22.39/m and 92x32 $14.93/m, & you may be able to get custom sizes.

I don't know about cedar chiselling well. It's too soft and tends to bend and fracture when you're chiseling across the grain regardless of how sharp your chisel is. It also tends to split and peel when going with the grain. I reckon that hardwood is easier to get an acurate finish when you're doing everything by hand (I'm doing the motises with a drill/spadebit and a chisel, and I'll do the tenons just by setting the depth on my power saw and making multiple cuts, tidying up with a chisel). Besides, I don't think cedar is as durable and it dents easily. I've got a dog that might be scratching on the styles when he's locked outside and if he does, then it won't take long to do some serious damage to a cedar door.
On top of this there's the cost. Cedar is another 50% on top of Hwd, so that's an extra $300 that I'll save. My main concern is that the stuff might move around and start twisting all over the place, but I've got my fingers crossed that once it's got lammy glass siliconed in, with four hinges on each leaf, it should be pretty stable. They'd better not send me a load of twisted rubbish to start with though.

Originally Posted by Andy Mac

Good luck with it.

Thanks for that. I should be getting the track tommorrow and I'll order the timber tommorrow as well so hopefully in a month or so I'll be able to post up some piccys of a fully operational bi-fold set up that folds flat against the outside wall. I've never seen one before, so it may be a world's first.
On the other hand, if journeyman Mick is right, then I could be eating my words and reconfiguring the set up in a more conventional way.

Pawnhead,
have you ever fitted any bi-folds? I have never seen any bifold mechanism that allows the doors to fold back against the walls. The door nearest the jamb is hinged or pivotted and the next door is hinged off it and suspended via a carriage to the top rail. As the doors open fully they touch and the carriage will prevent the doors opeining much more than 90 degrees. I'd be very interested to see a set up that allows the doors to open flat against the walls without utilising curved rails or something very tricky.

Mick

With no bottom track, as soon as they pivot open, they'll rock out of balance and jam against the floor.

Pick up an envelope and hold it vertically by one corner and you'll see what I mean. The only way to prevent this is to centre pivot, which means you have to build with a super high level of accuracy.

You can make them work of course, but it would be easier just to do away with the sliding mechanisms altogether and just barrel bolt panels into place and carry them away when you want them open!

Commercial bifolds have adjustments on the top AND bottom tracks to allow for the "drop", and they are by no means "set and forget".

I hope you have one big sucker of a piece of steel to hang all this from!

Cheers,

P

Originally Posted by journeyman Mick

Pawnhead,
have you ever fitted any bi-folds?

Yes, I've fitted a couple of sets before. I've been a chippy for 25 years, so I'm not exactly wet behind the ears.

Originally Posted by journeyman Mick

I have never seen any bifold mechanism that allows the doors to fold back against the walls.

Neither have I.

Originally Posted by journeyman Mick

The door nearest the jamb is hinged or pivotted and the next door is hinged off it and suspended via a carriage to the top rail. As the doors open fully they touch and the carriage will prevent the doors opeining much more than 90 degrees.

By having the track on an angle I can run it past the edge of the opening.
I've made an illustration in MS paint so you can see what I mean. It's a plan view.

Originally Posted by journeyman Mick

I'd be very interested to see a set up that allows the doors to open flat against the walls without utilising curved rails or something very tricky.

Mick

Hopefully I'll be able to show you.

Originally Posted by bitingmidge

With no bottom track, as soon as they pivot open, they'll rock out of balance and jam against the floor.

Yes, I know what you're talking about. With a 20mm stepdown I can afford to leave up to 10mm clearance from the floor, but you'll probably still have to give some support to the doors as you operate them. It's only the third leaf that will tend to pivot and scrape the floor at it's outside edge. If you give the door a bit of support by lifting the door handle as you open them then they should work allright. I can imagine that they won't be the easiest doors to operate, but if you know where to apply pressure, then they should work.

Originally Posted by bitingmidge

The only way to prevent this is to centre pivot, which means you have to build with a super high level of accuracy.

A central pivot won't work. The doors have to close against a 20mm step down for weatherproofing. With a central pivoting system, half of the door would end up inside, besides they still won't fold flat against the wall.

Originally Posted by bitingmidge

You can make them work of course, but it would be easier just to do away with the sliding mechanisms altogether and just barrel bolt panels into place and carry them away when you want them open!

Get real!

Originally Posted by bitingmidge

Commercial bifolds have adjustments on the top AND bottom tracks to allow for the "drop", and they are by no means "set and forget".

Bi-folds are supported entirely by the top carriage. I realise that being timber, they'll need the occasional 'tune-up' adjustment of hinges, track height, etc.

Originally Posted by bitingmidge

I hope you have one big sucker of a piece of steel to hang all this from!

I've installed a 300X63 Hyspan, but when I designed it, I didn't make any allowance for the weight of the doors so it's probably just a bit overspanned. As I mentioned, it's already sagged 5mm and I expect it to sag a bit more with the weight of the gyprock ceiling and the doors so I'll pack the track 20mm to give me some room for vertical adjustment. The carriages themselves have 20mm vertical adjustment, but I wouldn't want to use it all if the track goes 20mm out of level. That would lead to all sorts of twisting problems when operating them. The track has to be kept level.

Originally Posted by bitingmidge

Cheers,
P

Cheers, and thanks for the advice, but no one has talked me out of it yet so I'll order the timber now and see what happens. I like the idea of them folding flat against the wall, out of the way, and I don't want an ugly bottom track that would have to follow the same angle as the top track. It's not a commercial idea, because I know they won't be easy to operate, but the worst case is that I might have to reconfigure them conventionally with a bottom guide, but it's only a bit of my time that will be wasted.

Pawnhead,
okay, I can see what you mean to do, I'm just not 100% convinced that the geometry will work when the doors are travelling through the 90 to 180 degree range. I've got a sneaking suspicion that somewhere there might be a sticking point. If you've got a few hollow core doors hanging around off a job it might be wothwhile doing a dummy run. Oh, and by the way, some commercial bifolds do have a bottom track, not for support, but for alignment (the ones I fitted anyway)

Mick

Originally Posted by journeyman Mick

Pawnhead,
okay, I can see what you mean to do, I'm just not 100% convinced that the geometry will work when the doors are travelling through the 90 to 180 degree range.

Yeh, at the 180 degree position it will be inclined to jam in the track when closing.

Originally Posted by journeyman Mick

If you've got a few hollow core doors hanging around off a job it might be wothwhile doing a dummy run.

If it doesn't work then it's not a huge deal to just move the track in and install a bottom guide track, and if this track system I'm putting together doesn't work then I'll just have to shell out another $660 to centaur and get the proper goods. Here is the timber I'm going to use anyway http://www.barrenjoeytimber.com.au/price.cfm?CatID=11 F27 North Coast hardwood, whatever that might be. It looks alright in the photo, It just better be nice and straight when it gets here.

Quote:
Originally Posted by journeyman Mick
Pawnhead,
have you ever fitted any bi-folds?

Originally Posted by pawnhead

Yes, I've fitted a couple of sets before. I've been a chippy for 25 years, so I'm not exactly wet behind the ears. .........

Sorry about that, I presumed it was someone attempting the unknown or untried because they didn't know better, rather than someone whose skill and experience have led them to try something a bit different.

Mick (who's been known to do things that aren't supposed to be possible)

Originally Posted by journeyman Mick

Sorry about that, I presumed it was someone attempting the unknown or untried because they didn't know better, rather than someone whose skill and experience have led them to try something a bit different.

if he can get them to work, he will become a millionaire the first bi-folds to defy gravity seriously tho, good luck