I ordered a low aluminium threshold for my very large and very heavy patio doors. This threshold is 135mm wide, and made of almost nothing. The doors being extremely heavy need good base support. I could not have the threshold hanging over the cavity, so I placed a 10mm thick steel plate over the cavity wall, from outside brick all the way in to the internal blocks. The steel plate made a perfect flat and strong base to sit the patio doors on.
Unfortunately there are 4 issues which means I may have to strip everything out.
1) there is water sipping in under the threshold. The threshold is not fixed or glued to the steel plate and water can run freely under it. The steel plate does not even have an inclination, if anything it probably tilts inwards
2) The steel plate may form a thermal bridge, become very cold inside and generate condensation inside the room.
3) I fitted the steel plate badly and it is not perfectly plumb. The window fitters used packers here and there which has resulted in bending the threshold as it is very thin, very weak, and really does need a flat surface to sit on
4) If there is not a steel plate then my threshold, the aluminium frame's bottom, at 135mm width, will sit partially over an open cavity, and as it has a thermo block at the middle, I expect whatever hangs over the cavity will collapse. The cavity is only 50mm, but even so, there is no safe position for the frame while the cavity exists.
Use a cill? A standard patio door cill is made for frames of about 70mm-95mm, and even then some of the frame just hangs in mid-air as the cill drops away. But those frames are strong and can take having some of them overhanging.
I would need a special cill with a flat base of 135mm before it drops away.
On the photo you can see a standard 95mm frame sitting on a standard 150mm cill, as you can see some of it is in mid-air.
On the next photo you can see my threshold, it is very thin, 13mm, and not even a solid cast piece as there is the thermoblock in the middle.
How can I fix the above problems?
Unfortunately there are 4 issues which means I may have to strip everything out.
1) there is water sipping in under the threshold. The threshold is not fixed or glued to the steel plate and water can run freely under it. The steel plate does not even have an inclination, if anything it probably tilts inwards
2) The steel plate may form a thermal bridge, become very cold inside and generate condensation inside the room.
3) I fitted the steel plate badly and it is not perfectly plumb. The window fitters used packers here and there which has resulted in bending the threshold as it is very thin, very weak, and really does need a flat surface to sit on
4) If there is not a steel plate then my threshold, the aluminium frame's bottom, at 135mm width, will sit partially over an open cavity, and as it has a thermo block at the middle, I expect whatever hangs over the cavity will collapse. The cavity is only 50mm, but even so, there is no safe position for the frame while the cavity exists.
Use a cill? A standard patio door cill is made for frames of about 70mm-95mm, and even then some of the frame just hangs in mid-air as the cill drops away. But those frames are strong and can take having some of them overhanging.
I would need a special cill with a flat base of 135mm before it drops away.
On the photo you can see a standard 95mm frame sitting on a standard 150mm cill, as you can see some of it is in mid-air.
On the next photo you can see my threshold, it is very thin, 13mm, and not even a solid cast piece as there is the thermoblock in the middle.
How can I fix the above problems?
