Patchin up me porch

[zoothorn]

Hi again chaps,

 

Im finally on this job. My builder was here so asking what he'd do, he said yes ideally lime mortar as has been suggested.. but if it were him, might just go 4:1 mortar. So Ive had to go just mortar. Cost is £20 vs £120 including driving 150m to get 'lime mortar' ready mixed.. so turned out an unviable option with an old failing car.

 

Its been a very tricky for me so far tho- getting the stuff in the rough, craggy stonework has been very challenging.. so i can only do an average job at best. Most of the mix fell on the floor. A sod of a job i feel way out my depth with.

 

So far I've managed a 1st "pass" of mortar. But tbh I dont feel i really know what im doing. Am i rendering? With the same stuff? Does it need a second " pass" then a whole render over?? What the heck is this old stuff its replacing.. render or mortar? Its thick, covered the reveals, seems like a fine concrete maybe fk only knows (pic 3).

 

As it is Ive rough filled say half depth. But I'm not sure how to continue. Even my mix (1st time done one) i couldn't achieve it to 'stick' on the trowel.. so im not even confident on this, but, it seems possibly ok.

 

Thanks zoot.

 

 

[zoothorn]

[zoothorn]

Sorry the pics aren't too clear..

 

Could someone help me out? I'm not sure how long after my 1st repoint layer (of 4:1) I can put the 2nd layer? I needed 2 layers (or "passes" I dont know the right term) because the depth was so big between my stone. I think that was the right idea. So it's been 3 days curing.

 

Also how long does a bag of cement last, opened? do I need to store it in an airtight bag?

 

thanks- zH

[markc]

You could have done it in one go, but likely to sag. A day or so is more than enough time for the infil.

Cement will last indefinitely as long as it doesnt get damp, Roll down the top of the bag to expell the air and it will last weeks/months

[joe90]

Don’t stress, it’s a cottage, stuff like that is called “character “. Just tidy it up, don’t render over all the stone as that needs to breathe. When I do stuff like that I tend to finish it off with a brush when it’s nearly hard. Not too hard a bristle, paint brush will do, evens out the trowel marks and gives a rustic finish, which is what “cottage” is all about IMO ?. I have cement in my container 6 months old and still usable as it’s kept in the dry, top rolls down and a brick on it.

[zoothorn]

3 hours ago, markc said:

You could have done it in one go, but likely to sag. A day or so is more than enough time for the infil.

Cement will last indefinitely as long as it doesnt get damp, Roll down the top of the bag to expell the air and it will last weeks/months

 

Ah thank goodness. I can crack on with the 2nd 'coat' this wknd then. I hate wasting 20kg of cement you see/ so that's good, I might use asap after for another mortar job. Thx markc

[zoothorn]

3 hours ago, joe90 said:

Don’t stress, it’s a cottage, stuff like that is called “character “. Just tidy it up, don’t render over all the stone as that needs to breathe. When I do stuff like that I tend to finish it off with a brush when it’s nearly hard. Not too hard a bristle, paint brush will do, evens out the trowel marks and gives a rustic finish, which is what “cottage” is all about IMO ?. I have cement in my container 6 months old and still usable as it’s kept in the dry, top rolls down and a brick on it.

 

No good point. Doing every job the 1st time (mixing mortar- my 1st effort) innevitably means stress.. I convince myself it's all wrong & you lot are laughing at me. its a confidence thing.

 

There's character.. & a crap diy job though joe: I chipped off one crap '80's diy job, to only then replace it with another wasn't on the job sheet! I'm worrying close to this outcome as it is- so I need to up my game & tart up the remainder of the job best I can.

 

The reveals where I chipped off a 1" thick cementy-covering "render" needs consideration: I wonder whether I need a new "render" layer to replace it, after doing the 4:1 point job. I back filled the large voids around frame ok (builder told me just use mortar/ ok) so I sort of have a base layer to create new reveal bits.

 

Ok one thing that did occur, is why I didn't buy hydrated lime (looked on ebay today, 1kg £10) & put into my 4:1 mix, to make "lime mortar" more affordably than the suggested  3x £30 tubs.. but anyway a bit late now. Or maybe I'm not understanding what constitutes "lime mortar" (or the difference between this, & render, which has lime in 6:1:1 ?). I'm so new to all this you see: I try googling prior to asking on here but it's still not clear to me even still.

 

Thanks zoot

 

Another

[zoothorn]

Hi- if anyone could help. I'm about to do my 2nd layer of mortar between the stone. Once this is done, I still have the reveals to do: but I don't think mortar is correct for here, I think a render is (tho I might be wrong- I'm just making a guess I must admit).

 

Can I make render with the two materials I have (sand, cement), plus buying say a small ammount of 'hydrated lime'.. to make render of 6:1:1 ? Am I on the right track with this idea? I don't think, so far as I can establish, that using my mortar mix as a render for the reveals is correct.

 

Thanks- zoot

 

 

[PeterW]

On 08/04/2021 at 14:00, zoothorn said:

why I didn't buy hydrated lime (looked on ebay today, 1kg £10)

It’s £16 for a 25kg bag in Jewsons.... 

[zoothorn]

43 minutes ago, PeterW said:

It’s £16 for a 25kg bag in Jewsons.... 

Hi Peter. I know but 90% wasted assuming it wont keep. Im not up to speed with cement & lime having never used them before. I just need 1kg, i think, if my plan is the right to 'render' the reveals at all.
 

 

 

 

[PeterW]

If you really only want a kilo I would send you some but tbh it will keep in a plastic rubble bag and you can add it to all your mixes. 

[zoothorn]

30 minutes ago, PeterW said:

If you really only want a kilo I would send you some but tbh it will keep in a plastic rubble bag and you can add it to all your mixes. 

 

31 minutes ago, PeterW said:

If you really only want a kilo I would send you some but tbh it will keep in a plastic rubble bag and you can add it to all your mixes. 

Actually i know someone who could use the remainder, & i think i might need 2 kg. Thanks tho.

 

But do I even need it for this porch job- I still dont know. I suppose it makes no sense to point my 2nd layer with lime in the mix, if the prior layer is 4:1 sand/ cement.

 

The only thing therefore it could be used for, is to make render. But i dont know if my thinking of rendering the reveals.. has any merit. You see the stone sides (showing at the reveals) are far more uneven than their faces ( showing on the porch walls) which themselves are very uneven. So the reveals are seriously, seriously inny outy uneven.

 

Now, whoever did the job before me Im chipping off all hollow etc, seems to have seen this inny outy stone side reveals.. & evened them up with some form of mortar/ concrete/ rendery/ god knows what material. Therefore, its my thinking that i should replace it. But i dont know if this is correct thinking. And I dont know what to replace it with.

 

 

 

[joe90]

I would not worry about the lime fir the second coat as the first had none, it does make the mix a bit more easy to use but you could add a little plasticiser to it to do the same job.

[zoothorn]

2 hours ago, joe90 said:

I would not worry about the lime fir the second coat as the first had none, it does make the mix a bit more easy to use but you could add a little plasticiser to it to do the same job.

 

Hi joe. no understood re. 2nd coat. What I'm now considering, now Ive established that I can make lime mortar (assuming it's maybe 4:1:1 ?).. is toying with the idea of starting the job again. I think maybe it wasn't suggested to buy 25 kg bags x4, is my concern over waste (plus maybe hand mixing.. which is damn hard work).

 

Before I jump in & redo it all tho: I'm paintakingly trying to get the old wretched white fk knows what off which is welded onto to stone.. incredibly hard work, worst job yet, but over a week I can maybe continue & have the naked stone "presentable" without whitewashing it all.. if I can do a decent repoint job. It would make an interesting porch but a helluva job. But the benefits are significant, if it can 'breathe' (especially if there is a bit of damp at base in one corner) as far as I can gather.

 

So, if I continue as is with my 4:1 mortar & my naked stone.. it will look presentable. Now the stone has the white fk knows what removed.. can it breathe enough now? if so, could I do away with the idea of redoing the whole mortaring Ive done?

[Roundtuit]

You're not making lime mortar. Lime mortar has no cement in it.  What you are proposing is adding lime to a standard opc/sand mix, which acts as a plasticiser to make the mix more workable and lightens the colour up a bit.

 

I think 4:1 is unnecessarily strong tbh, but we are where we are.  I'd probably go 6:1, get it done and move on ?

[zoothorn]

7 hours ago, Roundtuit said:

You're not making lime mortar. Lime mortar has no cement in it.  What you are proposing is adding lime to a standard opc/sand mix, which acts as a plasticiser to make the mix more workable and lightens the colour up a bit.

 

I think 4:1 is unnecessarily strong tbh, but we are where we are.  I'd probably go 6:1, get it done and move on ?

 

Aha- I was wondering why joe90 said lime addition acts the same as a plasticiser, which lead me to think that perhaps then, lime mortar & mortar with lime in are two entirely sepaerate things. Omg I'm so confused.

 

Right.. so so on earth is the difference between lime mortar, & a mortar mix with lime in it then? crikey I've been brought crashing down to earth with my 1st attempt at a mortar mix. I'm a bit dispondent tbh. And very worried about the structure of my area around thye reveals which I cannot seem to get an action plan together to attack it.

 

Ok I think I have a problem then if you say 4:1 is "unneccesarily strong". Because I find my mortar seems weak & crumbly, & nothing like the strength (or the texture/ constituency) of the old stuff I'm chipping away in fact (whatever it is/ I cannot ID it, cement, mortar, concrete, render- but all I know its very strong, like a fine concrete or something).

 

I'm further confused by having made 1 successful concrete mix before (in a mixer), which the only basic difference to this mortar Ive concocted, was the addition of aggregate, & more water. As far as I can tell. But the results.. totally, totally different: one a sandy dark grey thick stuff > forming a weakish crumbly material, the other a light grey thin stuff > forming a rock solid material. How such different results from adding some hard core, IE gravelly stones & water??

 

I can only surmise the stones are added in concrete to add ballast/ volume.. not as some ultra atom bonding properties.. so I cannot think it through & glean any logic from it. SO confused.

[TonyT]

I wouldn’t have cement mortar any where an old stone build property and at every renovation opportunity take the chance to remove it.

 

Cement mortar traps in moisture, doesn’t breathe, doesn’t allow for any movement.

lime mortar allows allows all of that and it’s what the original structure would have been built with.

 

https://www.spab.org.uk/advice/lime

 

you have the internet with the worlds information and you tube videos showing how things can be done. Good luck 

 

[zoothorn]

Tony, I used the www for videos/ info. And if I go try it & things seem totally out of kilter, then I still do not understand some basics. I cannot go back & ask the www why or ask videos. So I ask on here. It is pretty much why the site exists. (you could just reply to every question asked on BH "you have the internet.. go figure it out" but you wouldn't).

 

I understand the inherrant difference between lime mortar & mortar, it's been simple to understand from pg1 being mentioned it's breathability. But I was here asking what the difference was between mortar with lime in, & lime mortar is (which HAS to be mortar with lime in.. surely.. so surely yiou could appreciate might be confusing to a newbie, no?).

 

My builder was passing, I ask him quick what he'd do in my porch. He looks at it. I say you chaps suggest "lime mortar". I expect him to concur of course he does, but also says "but heck I might just go mortar 4:1". So with due respect to the advice on here which I understand being the optimal choice, as he is a builder right here whose proven to be very competant (if not in his comms to me during the extention build), his alternate option of 4:1 must have some validity. It might not be optimal. It might not be your preferred choice either. It's not that I'm ignoring advice either. But a choice I explained why I made:

 

1) I cannot get lime mortar without spending £150 putting my old failing car at risk driving 150m to get tubs of it.

2) I cannot make lime mortar (I think.. but I'm confused as to what exactly it is ^as above)

3) my builder says just mortar 4:1 "is ok"

 

so then I simply have no choice but go 4:1 mortar (even if I'd prefer lime mortar, of course I would if it's breathable).

 

But, why my 4:1 mix seems crumbly I was questioning. Difference between concrete & mortar I was asking too: I go on www of course.. it says ballast, more water in concrete. If see two SUCH completely different materials I'm confused. So I ask on here. The one thing I have fully understood from pg1 is lime mortar's breathable/ best for stone/ optimal. It doesn't mean that I can choose it if not it's not feasably available tho, & there is a 2nd choice which is suggested by a builder to me that is readily available so I can at least try/ crack on.

[zoothorn]

Can someone explain how sand + lime hardens then if it has no cement in with it.. if I've I got it correct that lime mortar has no cement at all-? or am I barking up another wrong tree I wonder.

 

Is the lime put in a render mix, just added as a plasticiser.. not for adding any 'breathability' aspect then-?

Edited April 11, 2021 by zoothorn

[jfb]

Hydraulic lime is breathable and doesn’t go with cement.

Hydrated lime is what is added to cement to make it more workable and can lighten the colour. 

[zoothorn]

On 11/04/2021 at 15:20, jfb said:

Hydraulic lime is breathable and doesn’t go with cement.

Hydrated lime is what is added to cement to make it more workable and can lighten the colour. 

 

Hi there jfb. Great now I understand, Ive not been on board with the make up of this stuff. Right so as I can gather adding lime to cement/ sand, in a significant ammount, forms 'render'. But just a little ammount, is used as a plasticiser, forming 'mortar'. Is that right?

 

Ive still got the question of how lime + sand alone can act as a mortar (or act as a bonding material between stone maybe is a better way to ask) without there being any cement in. Is the word cement a generic term perhaps.. & lime is a cement? surely not or there'd be too much confusion.

 

thanks zH

[zoothorn]

@joe90 Joe I wonder if you could help. I'm still up a gumtree on this job taken me weeks now & I'm only half way through, understanding some, but not all the basics still.

 

I recall 33 yrs ago (i am capable.. just) as a labourer repointing a big old barn wall, cotswolds. Maybe it was lime mortar. Now afair, we repointed one day.. then came back perhaps the next day (?) & stiff-brushed off to a nice textured finish to the mortar. Now here, as Im doing this job in 2 steps (as I have very deep bits to fill) I need to apply a 2nd coat of 4:1 to my 1st. And try & recreate this nice 'textured' finish once Ive done my 2nd layer.

 

So I need to do 2 things: "prep" my 1st coat surface so the 2nd coat best bonds to it (most is dried, some 15 hrs 'new').. & lastly to do the texture brush finish job preferably without copious dust involved.

 

I have had some success, with the shallower pointing areas I needed only 1 pass on,  but it had dried fully: I gently went at it swirly motion with a wire brush... trying to recreate my textured idea from yonks ago.. & it worked out well. But... dust galore. Terrible job my eyes full of mortar dust. Bad newbie mistake re. dust, but thankfully looks good.

 

thanks zH

[joe90]

@zoothorn, yes lime is best fir old stone buildings but as this is such a small area, in a porch and not covering the stone just go with 4:1 and a little plasticiser if you have any, it’s such a small area it’s not going to cause global warming/fall down. It sounds like your old barn was lime, it takes much longer to go off which is why you brushed it the next day.  Using 4:1 sand cement will go off much faster so you need to brush it off after 1 or 2 hours with a fairly soft brush, it will still be wet enough to not be dusty but solid enough to not fall out/leave large marks. Crack on mate ?

[zoothorn]

2 minutes ago, joe90 said:

@zoothorn, yes lime is best fir old stone buildings but as this is such a small area, in a porch and not covering the stone just go with 4:1 and a little plasticiser if you have any, it’s such a small area it’s not going to cause global warming/fall down. It sounds like your old barn was lime, it takes much longer to go off which is why you brushed it the next day.  Using 4:1 sand cement will go off much faster so you need to brush it off after 1 or 2 hours with a fairly soft brush, it will still be wet enough to not be dusty but solid enough to not fall out/leave large marks. Crack on mate ?

 

Aha right. So Ive missed the boat again (15 hrs since) to do the brush off thing. Fk a duck. dust city for me again then. Live & learn.

 

Right but the best surface prep of the 1st coat, for the 2nd coat? I assume it has to be proper dried beforehand? it seems to get always-dusty once dried/ permanently so you see, hence I need all the help so 2nd doesn't just fall off onto my loafers joe.

 

I was wondering if weak pva solution was the ticket.

[zoothorn]

Could someone just help me out on the prep of a 1st coat of mortar, for best adhesion of a 2nd coat ontop? the 1st coat is fully dried unfortunately (the surface mostly smoothed out, to get it stuffed into the voids.. I forgot to rough it before it cured).

 

Assuming this 2nd coat > onto 1st coat isn't often done, a weak pva solution painted on to help?

 

thanks Zoot