Mortar for pamments

[fluffytail10]

I have searched the internet thoroughly but cannot find the answer to which kind of mortar i need to use with my old pamments. On some areas of the floor they are butted together without any mortar, but in other places the gap is about 1cm wide. These gaps constantly fill with dirt and dog fur and i lost a pencil down one of them - hence my feeling that they need re-grouting. The floor dates from 1600s and is lovely and wibbly wobbly -all the pamments being different heights with lots of grooves worn in them where people have walked. I don't really want anything bright white as it will look really odd - or will it just fade over time - the other grouting seems to have a pinkish tinge.

So i have bags of hydraulic lime, sand and cement at the ready - what do i do next? What mix should i use? How can i make it less white?

Any ideas welcome
thanks
x

 

[88v8]

It needs to breath, so no cement.

If you point the fat joints and not the thin ones it will look odd. So, with the hydraulic lime I'd use silver sand. It's sharp, so it works with lime, yet it's fine and will work into the thin joints. Mix 4:1 or thereabouts.
For the fat joints, make the mix quite stiff and compact it well.

Wet the pamments of course, and the bedding. Remove pencils.

Have a piece of old sacking handy to rub the overspill off the surface.

Quite a long job.
Yes it will look white, but with time will mellow.

Ivor

 

[fluffytail10]

thank you so much.....is that four sand or four lime?

 

[Flyfisher]

I should think Ivor meant 4 sand to 1 lime. I've used 3:1 myself for pamment grouting - with sharp sand for a more orangy colour - but I doubt the mix is too critical.

You'll likely get some of the mortar on the surface edges of the pamments and even if you wipe it off it might leave some staining due to the porous nature of the pamments - in which case spirits of salts will remove it when dry. This is basically hydrochloric acid, which is the main ingredient of 'brick cleaner', though brick cleaner is usually about a 5% solution whereas the spirits of salts I buy from our local hardware store is a much stronger 32% so it needs diluting accordingly.

 

[fluffytail10]

And is that one cup of lime 'powder' - or one cup of lime that's been mixed with water first?

thanks for your help - i have patio cleaner which hopefully will clear up any residue

 

[88v8]

Dry powder.
Mix the ingredients thoroughly, then slowly add water. It takes more time for the mixture to 'wet' than it does when mixing cement, so be careful not to over-wet it. I was going to say it should have the consistency of porridge, but that doubtless would open another can of worms.

To compact the mix into the variously wide/narrow joints, you might want to equip yourself with a variety of pieces of wood.

And some good knee pads. Even a small area is likely to be a three-Kitkat job.

Silver sand is sometimes more easily found at garden centres.

Ivor

 

[plasticpigeon]

If you want to change the colour you can use cement dye. I used some black cement dye to darken the mortar I used to point my quarries. i used some purpose made lime grout from Ty Mawr where the aggregate was very fine to get in the fine joints. I don't even know what the aggregate was it could have been fine sand or even stone dust. I would second the mopping with acid afterwards to clean up the overspill as it is impossible to do it so neatly that none gets on the pamments. In the Edwardian era I'm pretty sure pure cement slurry was used for grouting floor tiles bit that is definitely not a good idea on your very historic floor.

 

[bennoa1]

I used 3.5nhl lime and sharp sand (from B&Q) when I bedded and grouted the 9" quarries on our fireplace hearth, replacing a solid lump of concrete. It works well if you brush the surface before its dry to expose some of the stone in the mix which looks good. You'll need a wider grouting gap (say around 10mm) but as all the tiles will be slightly different sizes you'll probably end up with some wider gaps anyway.

 

[fluffytail10]

Thank you all so much.
Have just got to finish listening to the Archers and then i will begin!

Several sites suggest lifting badly damaged tiles and turning them over - does this work. I have a few with really deep grooves.

 

[bennoa1]

I've bought 3-4 bathes of these from different places, about 400 in total. They are all slightly different and some have flat backs others have a series of groves with raised bits so depending on what you have the other sides may not be smooth. Also they'll be coated in lime (hopefully not cement) and you may struggle to get the staining out. Maybe best to source some replacements and replace the poor ones. I've bought well but some are £5-£6 each so not bad if you only need a few but not funny when its hundreds.

 

[fluffytail10]

Well the job is done - only tool was a knife nicked from kitchen. This worked perfectly. The blade end for stuffing it in the cracks, and the handle for smoothing it off. I am amazed at the results it has lightened the entire floor and made everything look cleaner and neater, especially round the edges where there were gaps next to the skirting.

I guess time will tell if my mix worked :shock:

thanks for all your help

 

[Keithj]

Pictures would be good...

 

[fluffytail10]

Oh no it has all turned to dust! Noticed dust on the floor and realized all of it has turned to powder and is just brushing out of the joints.

what did i do wrong? should i have added hmm hmm CEMENT? The mix i used in the end was 1.5 lime to 4 sand - help

 

[Keithj]

Was this NHL or plain calcium hydroxide? Did you cover it and keep it damp?

 

[88v8]

Oh dear
Hmmm.
It needs to be NHL, that is Natural Hydraulic Lime.
Sharp sand/silver sand as mentioned, not soft sand (aka Building sand) although you might sometimes want a little soft sand for colour match of old work, depending.
The mix needs to be wet but not sloppy.
The joints must be clean otherwise there will be no adhesion. This might involve small brushes, pipe cleaners, etc, then a vacuum when dry.
Then the joints must be wetted before pointing but not swimming, a garden hand sprayer is good, keep wetting ahead as you go along.
It needs to be compacted into the joint, not just poked in, it has to be pressed down so the joint is really packed and tamped. Hence different width bits of wood for different joint widths.
After pointing, it needs to be lightly misted or covered with damp cloth for a couple of days sorry forgot to mention that. Lime-work in general needs to be kept damp while it hardens, or it will crack. A garden pump-up sprayer or a hand sprayer depending on area.
It follows that the room should not be hot, 60F no more, nor in direct sunlight.

Your job seemed very quick. Perhaps you only had a small area? The pointing I did in a room about 12' square, took several days, cleaning off with old sacking as I went.
Hard on the knees.

Ivor

 

[fluffytail10]

Well no there wasn' t much to do prob about 2 metres in total. Yes i think i should have kept it wet - as the damp area where the tiles are green and slimy has had the mortar set really hard. I did clean out the cracks etc last week as i knew id have to do it and retrieve the pencil etc. Is it too late to add water now? And yes the worst bit is next to the conservatory where it does in fact get quite warm. Well i shall try again xx

 

[plasticpigeon]

Sounds a bit unlucky, yes try again, hydraulic lime (which is often very pale grey or cream) which has a chemical set is less prone to cracking and disintegrating than hydrated lime or putty (which is pure white).

 

[rebeccac]

Just grouted a whole room with a bagged lime bio calce mix we buy in Italy it was with fine sand and marble. About half of the pavers move a tiny bit when you step on them -we laid into a sand/lime dry mix over compacted road base etc.

I now have large areas where the grout has dried then cracked making it loose.I have removed all the cracked bits.

Would I be better off shoving a very stiff sandy mix in first then grouting with my wetter mix in the last few mms ? Some joints are over 1cm some are only 3mm.

 

[bennoa1]

If its near the conservatory I'd wait until late Sept/early October before doing it as you risk it drying too quick which is maybe what has happened. You need to keep spraying the lime so that it doesn't dry too quickly. Its a pain to do but it could well fail if you don't. You could put a damp towel over the area but you need to keep it damp.

 

[88v8]

Just grouted a whole room with a bagged lime bio calce mix we buy in Italy it was with fine sand and marble. About half of the pavers move a tiny bit when you step on them -we laid into a sand/lime dry mix over compacted road base etc.

I now have large areas where the grout has dried then cracked making it loose.I have removed all the cracked bits.

Would I be better off shoving a very stiff sandy mix in first then grouting with my wetter mix in the last few mms ? Some joints are over 1cm some are only 3mm.

What a pain.
If the pavers aren't firmly supported they will move and whatever grout you use, it will crack.
Dry mix is a poor substitute for bedding them properly in wet mix, imho, and in any case dry mix will only go off over damp ground.

Once they're bedded and gone off, yes, by the sound of it the wider joints are not ideal for your fine grout, but if you use it for what amounts to a skim I suspect it may crack anyway. Are you using marble for the colour?

I would use NHL5 and sharp sand, or stone dust or silver sand (which is also sharp) for the finer joints, although mixing sands is likely to lead to some colour variation. The pavers need to be damp when they're laid and damp when you grout and, as has been said, kept damp while the grout goes off. A pump-up sprayer is a good way of maintaining moisture if you are there all day, or damp cloths or blankets if not.

The lime grout needs to be rammed in so the joint is filled and compacted, not just poked in with a trowel. You may need to cut some pieces of hardwood in various widths to use as rammers in your varying joints.
A long job to do a large area properly, hard on the knees.

Ivor