Repointing stone - patch or full repoint

joe90mitch

Hi all

Following my research and forum post about our guttering, looking up at our house made me notice a few areas where the pointing looks a little "amiss". There are a few areas where you can see it's gone too much, maybe a couple of centimetres. But this is in a couple of areas of the front and back of a 1890 Victorian terraced stone house. 

You can see an example below, just beneath our roof (ignore the green - this has been caused by a leak in the gutters which we are looking to get replaced in the next couple of months). There's probably only around 4-5 areas like this on the front and back combined and they seem fairly localised. The ones round back are perhaps a touch worse than the below photo - you can see the mortar is barely there on an entire side of 3-4 stones sporadically dotted.





You can see the general condition of the mortar and stonework above. The mortar itself is still somewhat flush with the stonework. There's a fair bit of discolouration on the stones - I think some will be from dodgy guttering (the left and right areas of the photos) so I hope the gutters will help stop some of that. But I guess also the black on the other bricks could be caused by damp due to cement mortar?

The other area of concern is at ground level at the front, to the side of our bay window. We noticed this autumn that our gutter was overflowing badly there, plus the aerial cable was going directly down into the wall, with no drip loop (this is our first house and first year living in it, so we're figuring everything out gradually ). I've added a loop to the cable and we got the gutters cleared and they no longer overflow there. However, I reckon this has been happening a good long while - you can see how green the stones are and there's a weed growing out. We also noticed at time damp showing on the internal wall directly inside - this has massively reduced since getting the gutters cleaned. Here the mortar must start about an inch in. The other ground level areas are in far better knick (under/to the right of the bay look similar to the higher areas, we have a covered alleyway down one side of the house, then we have a 15 year old extension out back that has a stone exterior with cement weatherstrapped pointing, but it may be OK as it's a newer build?)





The other small area of concern is around the bay window - where the stone meets UPVC. This mortar has cracked and fallen away in chunks:



Then, generally, it seems that whoever last pointed this house only took back the lime based mortar (the sandier looking mortar, if I've understood) what looks to be a few millimetres, then whacked some cement based mortar (the greyer stuff?) over. The cement bits fall off fairly easy (as I found when hammering in the coaxial clips - a tradesman who came round for a quote actually pulled off a few chunks of it by hand), but the lime doesn't come off with it.






So... if/when we get it all repointed, we'll definitely be asking for lime based only - and have already found a few tradespeople round here who offer that, which is good. However, I'm wanting to get a gauge of how people would approach this. Despite the cement mortar on top, we have no signs of damp inside the house other than the aforementioned gutter issues. To add to the equation, we are getting married this summer and also are committed to sorting the rotten gutters and also repointing our ridge tiles at the same time - so finances are a bit tight already

We had a guy out who said we really need to repoint the entire house. But wanted to check what other people thought. To me, the lime mortar itself only sits a tiny bit behind the stonework so other than the mentioned areas doesn't seem too bad? But I am a long long way from knowledgable about this so would be very appreciate of any suggestions.

One thought that crossed my mind was whilst we have scaffolding up for the gutters and ridge tiles to get someone to patch repoint those small areas for this year, then maybe in a year or two repoint completely (if people do say that's what's required).

Long post, apologies (typical me...). I guess my questions are, would you recommend sorting all of the above issues, or am I overworrying on some. Then, would you go whole hog and repoint the whole lot, or could we just do a patch repair - or even somewhere in the middle: do a patch repair this year then do a full repoint down the line. I appreciate a patch repair would leave us with unmatched colours in a few areas.

(For the full picture, I've contacted a few places for quotes/discussions and only had 1 out so far - he said about £2k for the full repoint with scaffolding)

Thanks in advance!

stuart45

The last repoint looks to be a waste of time as they didn't rake out the joints(rough guide is double the size of the joints for depth, usually about 20mm). Just sitting on top soon drops off.
Most of the joints look quite full. so with a flush joint finished with the churn brush it won't look much different from where the cement mortar has come away.

joe90mitch

Thanks @stuart45 - I agree that it seemed daft to put such a superficial layer of the top mortar on... Now unsurprisingly it's mainly falling off.

Considering you say most of the joints look quite full (I agree), do you think it actually needs a full repoint or do you think the guy might have seen the chance to upsell?

Then, is there much benefit to me (or getting someone in) to patch repoint the few areas (especially the lower bit that has suffered from the gutter overflowing for at least a year and probably much longer judging from the amount of crap that was in our gutter) or is it an all-or-nothing approach ideally?

stuart45

If it was my house I would patch point the worst bits. If most of the joints are full, and the mortar seems firm, I wouldn't rake out the joints just to re-fill them. New mortar never bonds to the old as well as the original mortar was.
When working for firms in the past I have repointed quite a few houses that didn't really need it.

joe90mitch

Thanks again We have a gutter/roofing company doing the new gutters and repointing the ridge tiles - they'll have to use scaffolding at the back and an access platform at the front - probably worth me trying to line up some who can do the patch repairs at the same time.

Is this something I could fairly easily try? I have seen on these forums that lime is a touch trickier, but in theory I'm thinking if the scaffolds are up anyway it could well be cheaper for me to quickly do it?

Should I definitely go for lime? I am assuming so, just wanting to make sure it's not pointless considering there's that top layer of cement looking stuff on top.

Finally, the guy who came out yesterday to quote said he wouldn't patch repair it as the mortar "is all ruined" (or something similar) - but all he did to try to demonstrate that was pull off a bit of the looser grey stuff. Is there such thing as "ruined mortar" - e.g. can I check for anything, like it being dusty, etc etc. Or is the fact it's still there and flush to the stone proof enough that it's ok for now?

stuart45

For some small patches you could have a go yourself.
Lime mortar would be better. There are different types of lime. Ideally the mortar should be similar to the original, just a touch weaker.
Perhaps he meant the sand/cement mortar on top was ruined. The lime mortar underneath looks OK in the photo.
Just feel the mortar gently with a knife. If it was really bad the weather would have taken it out.
If you have a really soft stone the mortar needs a softer lime. Mortar should be weaker than the masonry units.

joe90mitch

Thanks a lot Stuart - I'll see if I can get a good price on a professional doing a patch repair first, then.

The guy I spoke to yesterday has the specific lime mortar and sand to mortar mix he uses on his website, so considering I'd like to think he knows his stuff I could always try that as a starting point and readup on how to prep and apply. If the price for a patch repair comes in cheap I may just do that anyway considering I'd have to invest in the tools etc also.

On the mortar around the baywindow - is there a particular name for this? Is it offering any structural factors (e.g. holding in the window), or is it more a sealant around the edges? Would this need to be lime, or would this be a cement mortar?

Sorry for so many questions, but there's so much to learn in your first house, especially when the first half year of it was effectively lockdown Thanks for all your help.

stuart45

Forget to mention that this is not the best time of year for lime work.

joe90mitch

stuart45 said:

Forget to mention that this is not the best time of year for lime work.

Yes - I am happy to say that I've put my research in and knew that If the roofers are happy to share the scaffolding, I was hoping to book them in for more like April time which I think is better?

Another reason I'm wary of the guy who told me £2000 for a full repoint was that when I said I didn't think it was best to do lime work currently he said it's pretty much fine all year round (bear in mind we're up in Sheffield, so it's low temperatures!).

stuart45

joe90mitch said:

On the mortar around the baywindow - is there a particular name for this? Is it offering any structural factors (e.g. holding in the window), or is it more a sealant around the edges? Would this need to be lime, or would this be a cement mortar?

That's just a sand/cement fillet, not structural. Fills the gap between the frame and wall. Lime mortar would be better. Nowadays most people use sealant, although on older properties with timber windows burnt sand mastic was used.

joe90mitch

Thought so! Thanks once more, really appreciate it