repointing

[Dave2010]

hey guys, again

currently been repointed and the guys have raked out 7-12mm in most places (give or take a few mm)
I asked about going deeper and they say thats the depth your supposed to go to? TBH the mortar underneath looks quite sound once the surface has come off but having read the devilish internet many sites say many different things regarding depths, as they always do.

Any advice?

 

[stuart45]

7mm is not really deep enough.

 

[Alastairreid]

Sounds fine to me, mind dampen down the joints before re-pointing.

 

[Dave2010]

hmmm a difference of opinion. I was expecting about 20-25mm in all honesty

think ill ask again tomorrow

 

[joe-90]

What kind of mortar is it that you are raking out? And if it looks fine at 7mm did it really need doing?

 

[Dave2010]

What kind of mortar is it that you are raking out? And if it looks fine at 7mm did it really need doing?

erm...mortar type stuff LOL sorry but i've really no idea. It's very dark grey almost black.
The surface was terribly crumbly and it appears to have been flashed over before we purchased. Was at the point where a strong breeze would blow out a chunk.

 

[stuart45]

20mm - 25mm if the mortar is in poor condition. Joe makes a good point though about whether it needed repointing. There was a time when surveyors reports made the Lenders get the buyers to repoint walls within a time period on walls that didn't really need doing. If you have to grind out the joints down to 1/4 inch deep they probably didn't need doing to start with.
I've seen jobs where the pointing has dropped out 10 years later because the original mortar was so hard the bricklayers found it too much hassle to go deep enough.
Does sound like it has been repointed before not deep enough and it's only had the new stuff that failed taken out.

 

[Alastairreid]

10mm is adequate...25mm is extreme.

 

[joe-90]

My guess is that it was originally done in lime mortar then repointed with OPC. If that's right you should really go back to lime mortar again.

 

[EB1caneyeB]

If a strong breeze is blowing out chunks of pointing........ then i would grind out 20mm. Whats the point of having it done if isn't going to be done properly ?
You could grind out 5mm and make it 'look' like a good job. But re-pointing that thin will be at risk from harsh weather especially hard frost.

The guy doing the job may want to charge you more if you insist on this.

Any quote i give for re-pointing includes grinding out 20mm. It surely is the only way you can guarantee that the job you do will last more than just a few years.