How can I point these flags...and what with?

[MdB]

MdB, at that temperature, does the wax stay relatively hard then? Enough to sweep over or hoover?

Beeswax melts at 62°C. You will have to experiment to find out what it is like at heated floor temperature.

Your underfloor heating sounds so snuggly!

Hopefully it will be soon. Currently it is a horrible concrete floor covered in tools...

It is nice to walk on in bare feet which is more than you can say for most concrete floors.

 

[Andrew Bodenham]

DWB,
Facing a similar task of pointing some slate tiles I used a 1:2 lime:fine sand mix, and it's worked very well. You need to put it in properly mixed, not as dry ingredients. Don't add too much water though, you need the mix to be pretty stiff - almost like pastry before you add the water. In this way you can ram it into the gaps (using fingers, bits of stick, edge of credit card or whatever works) and finish it by brushing off with say a 2" paintbrush. You're aiming to get the gaps well filled, and finishing just below the surface of the flags. Any smearing on the face of the flags can be removed with a just-damp sponge. If the flags are very absorbent you could spray them with a little water first, or I suppose you could apply your oil / wax finish before grouting - this would also help to prevent any surface staining.

I'd mix up a sample first with your chosen sand to see how the dried colour turns out. The colour of the sand you use will have a big effect on the final look.

Finally, I can't say how what effect the UFH will have if you grout with a lime mix. It may be that the open gaps are acting as expansion joints, and if you fill them with rigid material the expansion has to be taken up elsewhere, e.g. at the room edges. What are the flags bedded onto? Is it something flexible that will accomodate thermal movement?

 

[Penners]

You could try something like these.

I wonder why Maplin sell knee pads. How many people build computers/radios/digiboxes/etc. while kneeling on the floor?

 

[Tom]

@ Andrew

The flags are laid in sand/lime 3:1 on top of LECA and Limecrete. The gaps are only there because the flags aren't perfectly square. I told my builder I wanted the gaps as close as possible because I hate floors with massive gaps...even when they're pointed up.

The more I think about this, the more I think that it would be best to get them oiled first to protect them. I'll let everyone know how it goes

 

[Flyfisher]

You could try something like these.

I wonder why Maplin sell knee pads. How many people build computers/radios/digiboxes/etc. while kneeling on the floor?

Yes, that was exactly my thought when that link came up almost top in my search. I suppose electricians spend time crawling around attic spaces, but then I don't suppose professional electricians buy their materials in Maplin. Seemed like a good price though - mine cost £12 and I thought that was quite cheap.

 

[HelenS]

Could you use low tack masking tape around the joints to protect the edges? It would take ages but may protect your lovely flags.

just a thought

 

[Tom]

Could you use low tack masking tape around the joints to protect the edges? It would take ages but may protect your lovely flags.

just a thought

I don't think it would work but thanks for the thought. I think they're too porous for a low tack tape to stick and the edges are wavy....and I have about 750 square feet to do :shock:

 

[c r]

Hi

I've no affiliation with this company, but have used one of these before, and it works quite well when using mortar containing the coarser sands that are often required when working with lime- the nozzle doesn't clog up (much).

http://pointmaster.co.uk/?gclid=CMaFmqqJ0qQCFQz-2Aod8xuNMQ

Yes the gaps in your floor look quite fine, so you yourself would probably have to make the supplied nozzle a bit narrower to suit. Which would then of course be more liable to clog up...Unless a consistently fine grade of sand is used in the lime mortar.

I've found the above pointing gun, no matter what grade of sand is used, to be more controllable than the commonly available ones, that have the cone shaped/pointed nozzle.

just a thought.

 

[Tom]

Thank you, I'll have a look into this