Bifold door support

[saveasteading]

We will have this opening for a bifold door. Big and heavy, and moving so it must not jam.

 

Looking for any experience of issues from such a  door deflecting.

Its not the Engineering in question but any idiosyncrasies of such doors.

 

We have two choices.

 

1. a steel macross the opening. \there is room for 178mm RSJ and then timber around it. It would sit on timber so we would add 2 more uprights at each end.

 

2. Simply retain the timbers as currently designed and plate both sides with high quality 12mm plywood, and screws every 150mm. The ply could be whole sheets so say effectively 1200mm high, but 600mm will surely suffice.... the outside will be faced in osb anyway. This make it an immensely deep timber beam of the James Jones / Pasquill type.

we would probably add suds between the horizontals to ensure a precise level beam before plating. And perhaps noggins/ dwangs at the top of the 600 sheet.

the timbers are 6 x 2 tanalised.

 

 

 

You may get the idea that I like the latter, because it is a neat composite design, and we dont have any issues how to fix the door. But my only doubt is in the  reality in use: do bifolds  

 

[MikeGrahamT21]

I can honestly say I like mine, but my opening is only 2m, I would imagine with the amount of leaves you are planning as above it could start looking quite cluttered when they’re all stacked up fully open, and may well look cleaner with a sliding door, but if you are set on bifold, then yes they are good, as with most things, if you get a good one. Don’t get top hung as they aren’t as robust as ground bearing. If PVC, Liniar modlock are very good, what I’ve got, 10 years in and they’re as good as new, just don’t get chrome hardware outside!!

[Andehh]

We opted for big sliders, as 85%of the time it's all closed up, so maximum glass views. Lot less to go wrong as well! 

[Super_Paulie]

not sure how much use this info is but i have some 4m bifolds, but under a steel beam and there has been no deflection. All work fine the last 10 years, it was the glass with integrated blinds that kept packing in. The beam was probably massively overspec.

[Spinny]

Aluminium Bifolds 3.5m wide and 2.4m tall, top hung, stack can be positioned to either side of opening when open.

Fixed to timber and steel beam above. (The timber was added because we changed the choice of doors and the height of the opening had to be reduced to suit.)

Best to have professionally fitted by careful, conscientious and experienced fitters.

 

Getting the threshold position correct is critical if you want something close to a level threshold, so knowing where the finished floor level will be.

PROCESS: Prepare opening, survey measurement of opening and marking of reference level markings around the area, detailed drawings with tight opening size, bifold manufacturing size etc, carefully check drawings and amend as necessary then sign off drawings, send to manufacture, professional delivery and installation, test and acceptance.

 

Beware the limited accuracy of laser levels. The company claimed floor level had been changed between survey and fit but this was nonsense. Their lasered levels differed by 11mm over 9m from survey to fit because laser levels clearly not reliable/calibrated. My water levels showed they were wrong. So buy a water level and mark careful reference levels.

 

Make sure the fixing methods and positions are defined and there is going to be solid material in the right positions and alignment for the frame to be fixed to. Insist on careful preparation, inspection and checking of the opening - builders lie and cover up - thus in our case the first fitting visit was abortive.

 

 

Edited 9 hours ago by Spinny

[G and J]

Echo buy good quality. We've just left a house with 23 year bi-folds, loved them BUT they faced the west (lovely views) but as they aged, when the wind blew across the plains of East Anglia they were both drafty and deflected and they weren't quite 2m. They were however top hung