Hi all,
Apologies for what is probably a very basic question ...
We have cracking in the mortar of the brickwork above the ground floor front window on our house. It's a mid-terrace house that was built in the 1930s by the GLC, and the walls are London yellow stock cavity walls. These houses were originally built without lintels, and the heavy timber frame of the window would have supported the brickwork above. However, the original timber windows have previously been replaced by UPVC windows and, like the majority of houses in the estate, this has caused bowing and cracking in the brickwork above the ground floor front window. There is also more pronounced cracking in the brickwork above the front door, but the door frame is still original, so this cracking appears to be caused by a different type of issue (i.e. not bowing).
We've had several quotes for installing a cat-nic (or similar) lintel above the ground floor front window, and repointing / remortaring the brickwork above this window and above the front door. These quotes have ranged from £700 - £1200. All of the builders who have quoted so far have said that it will be fine to use a cement based mortar, and that they will try to match the colour of the surrounding original mortar by adding dyes to the new cement mortar.
Being a complete noob at this sort of thing, I've tried to look at various sources online to check whether this all seems to be along the right lines. The main warning that I've seen crop up is whether a cement-based mortar is appropriate for this type of brickwork (i.e. 1930s London yellow stock). I've read that if the cement mortar is harder than the bricks, then this can cause problems with moisture in the bricks, and can mean that if there's any future cracking then the bricks might crack instead of the mortar.
I'd be really grateful if anyone is able to give me some advice as to whether a cement-based mortar is likely to be appropriate for this type of brickwork (i.e. 1930s London yellow stock) ... ? If not, then what should we be using instead - someone else mentioned a cement-lime mortar mix, but most builders don't seem to do this ... ? We're also quite worried about whether the colour of the mortar is likely to match the surrounding original mortar. It's quite a prominent position on the front of the property, and where this job has been done badly (which sadly is not uncommon on other houses on the estate) it's very noticeable. Does anyone know whether there is any certain way to get a decent colour match - or is there always an element of pot-luck ... ?
In case it helps, here are links to a couple of photos ...
- The first photo shows the cracking in the brickwork above the ground floor front window and above the front door. None of the builders who have provided quotes have been able to say for certain what is likely to have caused the cracking above the front door, but such cracking is common on houses on the estate.
www.planningjungle.com/photo1.jpg
- The second photo shows a close up of the brickwork at the bottom of the window, just to show what type of mortar was used. For comparison, I've chosen an area where you have original mortar (on the left, as remains on almost all of the house) and some new cement mortar (on the right, just a bit around the window cill, which has been done very badly). The original mortar seems to be in very good condition - it's firm (not at all crumbly), although you can make slight groves in it with the edge of a key, so it seems to be weaker than the cement mortar.
www.planningjungle.com/photo2.jpg
Any advice would be greatly appreciated - sorry for asking what are probably silly questions - but it's something that's been worrying us for quite some time ... !!
Thanks
Steve
Apologies for what is probably a very basic question ...
We have cracking in the mortar of the brickwork above the ground floor front window on our house. It's a mid-terrace house that was built in the 1930s by the GLC, and the walls are London yellow stock cavity walls. These houses were originally built without lintels, and the heavy timber frame of the window would have supported the brickwork above. However, the original timber windows have previously been replaced by UPVC windows and, like the majority of houses in the estate, this has caused bowing and cracking in the brickwork above the ground floor front window. There is also more pronounced cracking in the brickwork above the front door, but the door frame is still original, so this cracking appears to be caused by a different type of issue (i.e. not bowing).
We've had several quotes for installing a cat-nic (or similar) lintel above the ground floor front window, and repointing / remortaring the brickwork above this window and above the front door. These quotes have ranged from £700 - £1200. All of the builders who have quoted so far have said that it will be fine to use a cement based mortar, and that they will try to match the colour of the surrounding original mortar by adding dyes to the new cement mortar.
Being a complete noob at this sort of thing, I've tried to look at various sources online to check whether this all seems to be along the right lines. The main warning that I've seen crop up is whether a cement-based mortar is appropriate for this type of brickwork (i.e. 1930s London yellow stock). I've read that if the cement mortar is harder than the bricks, then this can cause problems with moisture in the bricks, and can mean that if there's any future cracking then the bricks might crack instead of the mortar.
I'd be really grateful if anyone is able to give me some advice as to whether a cement-based mortar is likely to be appropriate for this type of brickwork (i.e. 1930s London yellow stock) ... ? If not, then what should we be using instead - someone else mentioned a cement-lime mortar mix, but most builders don't seem to do this ... ? We're also quite worried about whether the colour of the mortar is likely to match the surrounding original mortar. It's quite a prominent position on the front of the property, and where this job has been done badly (which sadly is not uncommon on other houses on the estate) it's very noticeable. Does anyone know whether there is any certain way to get a decent colour match - or is there always an element of pot-luck ... ?
In case it helps, here are links to a couple of photos ...
- The first photo shows the cracking in the brickwork above the ground floor front window and above the front door. None of the builders who have provided quotes have been able to say for certain what is likely to have caused the cracking above the front door, but such cracking is common on houses on the estate.
www.planningjungle.com/photo1.jpg
- The second photo shows a close up of the brickwork at the bottom of the window, just to show what type of mortar was used. For comparison, I've chosen an area where you have original mortar (on the left, as remains on almost all of the house) and some new cement mortar (on the right, just a bit around the window cill, which has been done very badly). The original mortar seems to be in very good condition - it's firm (not at all crumbly), although you can make slight groves in it with the edge of a key, so it seems to be weaker than the cement mortar.
www.planningjungle.com/photo2.jpg
Any advice would be greatly appreciated - sorry for asking what are probably silly questions - but it's something that's been worrying us for quite some time ... !!
Thanks
Steve
