locking bolts for french windows

[JohnD]

these are a pair of rebated french windows. The insurance requires them both to have bolts with a removable key top and bottom plus a mortice lock. They currently have ERA push bolts with a cut cylinder key, but I observe each bolt has only two fixing screws, one top, one bottom which are 3.5mm x 35mm. The bolt housings are about 100mm high. The doors are on a stone step with a thick steel water bar so it would be difficult to drill it out for mortice rack bolts and it might crack. The surface-mounted ERA bolts go into the wooden sill just inside the water bar, and the bar prevents them pulling outwards.

The fixing bolts for the screws look a bit small to me. What do you think? The bolt housings might take 4mm at a pinch but not more as the heads pass through holes in the bolt and into recesses in the casing.

 

[HandyHands]

What about fixing mortice bolts to the top of the doors, and leaving the push bolts on the bottom ?

Are the french doors outward or inward opening? If outward, then I'd also consider fitting hinge bolts to prevent the hinges being drilled and the doors lifted.

 

[JohnD]

they open outward, and I have got hinge bolts.

yes, I could fit rack bolts at the top, but I like the idea of using the same key all round.

Thanks!

 

[HandyHands]

If the screws came with the product - then they will have been tested along with the bolts and housings. If they needed larger screws - they would be supplied with them. I wouldn't worry - 4 of these with a mortice lock is going to take a fair bit of punishment. Anyone that keen on making an entry - will do.