Best practice when finishing horned cills

[Build-H]

Currently gathering quotes for new windows from a number of window companies. Some prefer to silicone around the horns of a window cill and some prefer to cut into the brick and mortar around the horns.

 

Those that like to silicone argue that cutting into the brick looks messy, others argue that silicone discolours and cracks. 
 

which of these is the best way to do this? 

[Canski]

The problem seems to be the horns. Why have horns ?

[Gone West]

I haven't fitted windows with horns since the early nineties.

[Build-H]

Most timberlook windows such as Residence are typically installed with window cill horns to make them look more authentic, especially if they are fitted with a Radlington cill on an older property.  
 

Having horns isn’t a problem - I was seeking advice on the best way to finish them. There are too many window companies out there that cut corners unfortunately, and they want to do the very least / easiest install for the most pay. 

[Build-H]

On 03/01/2025 at 12:59, Gone West said:

I haven't fitted windows with horns since the early nineties.

Thanks for the helpful answer. 

[Gone West]

16 minutes ago, Build-H said:

Thanks for the helpful answer.

Thirty years ago I neatly cut the bricks out and mortared around the horns.

[Mike]

Horns aren't a traditional feature of windows. They were added when timber window manufacture became mechanised in the 2nd half of the 20th century to add strength during transport, with the intention that they should be cut off when installed. In mass-market housing they were often left on to cut costs.

[bmj1]

Not sure what a window sill horn is - do you mean window sill 'stools' ?

 

Window sill stools

 

Window horns

 

[Blooda]

An old thread here ^^^^

[Canski]

On 05/01/2025 at 16:49, Build-H said:

Radlington cill

If you are intending to install the frames after the masonry is complete and are absolutely sure you want old style horns then a solution to ‘the old thread’ could be….DPC on top of the cill to allow slip movement. Then mix some slurry primer and paint it on to the exposed brickwork ( not the front) prior to filling with mortar and pointing. Cut off any excess DPC and seal.