Replacement Windows Question

[Bill]

Hi All,

Should the window cill be fixed to the window in some way? If so how?

I am getting differing advice. Some say yes, others no. It may be that each is right in particular circumstances, but anyone here got the answer please?

Cheers. Bill.

[cj]

Hi You don't specify the type of window or internal /external cill. However IME pvc windows sit on the external cill between raised slots and are not fixed just placed into the slots. Internal cills are usually MDF just butted to the window and sealed with silicon. Wooden frames usually are supplied with the external cill attached as part of the frame and the inner cills are secret nailed to the wooden frame. Metal frames vary but most are bolted to the cill before glazing.

HTH

CJ

[Bill]

Sorry CJ,

The windows I am referring to are uPVC and the cill is external. Unless I've missed something the cill does not clip into the window frame although you have got me thinking now!!!!

Regards. Bill.

[Tuthledeen]

There is normally a channel in the cill into which the window locates but does not fix. To fix the cill to the window it is necessary to drill a pilot hole through both upper and lower faces of the cill into the lower face of the window frame (driling in an upward direction when the frame + cill is correctly oriented so there is no downward leakage path for water). Apply a thin bead of silicone to the cill contact face before assembly and then secure cill and frame using brass or stainless steel fasteners. Take care not to overtighten as plastic threads strip without much warning/.

[cj]

HI bill Pvc yes the cill has raised plastic rails which form a chanel to locate the window ,in the trade they use double sided glazing tape to hold it or if they need to hoist it up a ladder fix it from under the cill into the frame using self drilling screws. (warning the frames are manufactured with an aluminium rail inside the plastic to give strength on larger frames so you will need metal piercing screws)

HTH CJ