How to fill gap in cornices?

[ChrisA]

 

 

Hi everyone, 

I am about to fill these gaps between the wall and the cornice …it was previously filled in this what I think is no more gaps but I wanted to know if anyone has any other better ideas …I have tried all purpose filler and no more gaps in the past in other rooms but it just cracked again after a few months.

I was thinking about cornice cement but it is very hard when it dries.

I would really be grateful for any good suggestions.

Regards 

Chris 

[MitchellMc]

Hi @ChrisA,

It sounds like the cracking you’re experiencing is due to movement between the wall and the cornice, rather than the filler itself. Silicon-based products are usually flexible enough to accommodate minor movement, but if the gap is large or there’s significant ongoing movement, even silicone can tear away. Traditional all-purpose fillers or cornice cement are much harder when dry and won’t cope with this movement, which is why they tend to fail in these situations. You might need to physically fix the cornice in place with screws to prevent excessive movement, then fill the gap with a silicone-based filler.

Here's a helpful guide: How to repair a cracked cornice.

Please let me know if you have any questions.

Mitchell

[ChrisA]

Thankyou very much for your response…I do have a tube of the 3in1 and will use that …I was thinking of putting expanding foam in first and then the 3in1 as some parts the gap is fairly wide…do you think this is a good idea? 
thanks again!

[MitchellMc]

I wouldn't @ChrisA. Expanding foam may push the cornice further out through its expansion. If the gap is too deep or a large gentle push in some gap filler rod.

Mitchell

[ChrisA]

Ok thanks…I have some of that as well.

Regards 

Chris 

[ChrisA]

Hi Mitchell,

Thanks for your advice…I was thinking of adding screws as you suggested in the tutorial…but the wall is made of brick …can I still do it ? I would have to drill into the brick?

[JacobZ]

Hi @ChrisA,

Yes, you can still use screws, but you would need to drill into the brick. These Ramset Black Countersunk Masonry Screws would be a good option.

Let me know if you have any further questions.

Jacob

[ChrisA]

Thanks very much…I would have to pre-drill and use a hammer drill? 
Regards Chris

[JacobZ]

Hi @ChrisA,

Yes, you would need to use a hammer drill to predrill pilot holes.

Those screws need a 10mm pilot hole, so you would need to use a 10mm masonry bit.

Let me know if you have any further questions.

Jacob