exterior door frame Cill/ Threshold Sealant / Slab

[james19000]

Would anyone like to recommend what sealant to use for fitting a new exterior door frame cill to stone slab.

From what i've been reading online...

Silicon? : good option but is it good for sticking to wood? & Flexible?
Urethane? not as good a durability as Silicon
Caulk? not as flexible as above...

considering above thought about this stuff.

http://www.screwfix.com/p/unibond-frame-silicone-sealant-white-300ml/52113

http://www.wickes.co.uk/geocel-201-polyslphde-slnt-gry-380ml/invt/226526/

other suggestions greatly appreciated...

 

[noseall]

Fit the frame leaving a gap beneath the sill.

Foam the gap.

Trim off excess foam and hack it back say 25mm or so, then point with mortar.

 

[BigIan]

I would do as Noseall states but would use a suitable exterior silicone frame sealant and not mortar and heres why:

1) Thresholds of doors tend to get trodden on and so deflect / move which would crack the mortar.

2) You will need a selant joint around all edges of the door, using the same selant all the way round removes any joints and so less ingress of water.

3) You havent stated what the door is made from (PVC or Timber) If it is a timber door then these will naturally expand and contract with the weather and as such would be likely to crack any mortar jointing.

This is if you don`t have a large gap at the bottom, if you do this is another question to be dealt with when you can provide more information.

Ian