Gap between window frame of timber

[huw]

Hi,

We've now been in our house (C17 Grade 2 near Evesham) for 1 year and starting to look at stuff that needs to be done...hopefully nothing tooo major - but you might se a few posts here!

The first one is a gap between a new-ish window frame and an original timber. Looks like the concrete has fallen out.

It is quite a deep gap - as hopefully the picture will show.

I have been reading posts on this very interesting, supportive and I'm sure will be very useful forum...and I now know what oakum, burnt sand mastic and lime mortar is - and I have a feeling that those might be involved in the solution.

I am trying to find a builder to help - but they seem to be busy at the moment - but it would be useful to get some opinions on what to do - either to validate what any builder I might find suggests or if I have to roll up my sleeves and do it myself.

There is probably some discussion on what is coating on the timber is - we have some

Thanks in advance

Huw

 

[Cubist]

Hello Huw and Welcome to the club,

Yours is a common issue with timber frames and results from the expansion and contraction of the timbers during the seasons and of course other movement. Its a job to which there will be regular returns over the years of your stewardship. You may, just may, find a builder in your locale with both the experience and willingness to take the job on but I wouldn't hold my breath. If though, you're not comfortable taking the work on yourself, please make sure that any prospective provider uses the appropriate materials and methods. Your research thus far is correct and will help you but if needed I, and others, will be happy to provide more advice.

Cheers,
Cubist

 

[Cubist]

Sorry, I should have added that the caulking is a job best left until the late spring and summer months, particularly if a lime render is to be used for the final finish.

For now though I would urge you to get a supply of oakum to pack into the wider cracks and for any very narrow gaps some caulking cotton. This will help stop water ingress from driven rain and the final finish can be left until next year.

 

[huw]

Thanks @Cubist - I was going to ask - do you "just" ram oakum into the gap until it is filled - then render over the top...couldn't quite see where the burnt sand mastic was involved - as the YouTube's I saw seem to use it on the top

 

[Cubist]

Its an either or situation. Burnt mastic would be used as a final filler between sections of timber like your window frames and the house frame; it can also be used to fill large shakes (cracks) in the beams. Yours have been finished with a render of some sort and most of that seems to have been damaged, you'll need to rake it out. When packing the gaps with oakum or cotton make sure to leave about 5mm (up to 10 at a push) for the filler material.