Our bi-fold doors accept a 28mm glass unit which is 4/20/4 in terms of glass and cavity.
If your new door is going to be fitted in a new opening, by this I mean an opening which has not had anything fitted there previously, the measuring technique is quite simple.
Assuming that the door is going to be fitted between brickwork and that the aperture is square and level, you should deduct 10mm from the total brick-to-brick width and also make a 10mm deduction from the brick-to-brick height.
Due to their being many different types of door installations it is very difficult to identify every scenario. Therefore we would strongly suggest that you consult your builder for this information so that there is no ambiguity regarding the sizes.
This is one of the most difficult questions to answer. We are currently working on an installation video and written guide but for now we can give you some good generic pointers which will help you achieve that perfect fit.
The most important thing when fitting any aluminium product especially folding sliding doors is that the outer frame is installed true, plumb and square in the opening. To know when this is correct you should expect an 11mm gap between the sashes and outer frame all the way around.
Make sure that you always put your fixings through the polyamide break. You should always try to avoid fixing through the aluminium directly. You must ensure however the you do not over tighten the screws or you could crack the thermal barrier. Consider using a washer.
Once the door has been fitted correctly, before you put the glass in, make sure that the door slides freely with no glass. If it does, you can put your final fixing screws in the hinges.
Remember to ‘toe and heel’ the glass units. If this is not done, your traffic doors may drop and stop the door working completely.
The frame depth of the bi-fold door is 70mm.
The standard threshold we offer is 50mm high.
We do offer a lower threshold which is only 20mm high (DV173)
The DV173 low threshold does have the facility to have small aluminium ramps fitted at no extra cost. With the inclusion of the ramps the threshold will comply with Part M of the Building Regulations (DV174).