Lime morter?

  1. dobbslc

    dobbslc Member

    Messages:
    2,455
    Location:
    Hertfordshire UK
    I'm building a new fireplace suround and hearth with reclaimed bricks and was thinking of using a lime morter to give it that old traditional look. Is it worth the extra expense? It's the first real brickwork I've done that's not going to be plastered over so I want it to look good....
    What's the best type of sand to use and at what mix? :thumbup:
     
  2. gaz1 Member

    Messages:
    3,820
    Location:
    westyorkshire
    if you do its a special order for lime as the bag only lasts 10 days then goes off

    the steel job Im on has to use it on the walls and for the cement rendering

    im not to sure if I could get you a bag for yours to be done
     
  3. pod70 Member

    Messages:
    30
    Location:
    Kent, England
    Lime Mortar comes in 2 forms - Buckets of putty which is the traditional method and as long as there is a layer of water over the putty, it will last for months. You can buy just the putty & mix in sharp sand manually (but not in a conventional cement mixer as the putty will ball) or buy tubs or pre-mixed product, normally in a 3:1 ratio.
    The other method is to purchase the product as a powdered form which comes in 25kg bags and is mixed with water the same as modern cement. There are 3 main grades of powdered lime (Natural Hydraulic Lime) NHL 2, NHL 3.5 & NHL 5. For an internal fireplace NHL 3.5 should be fine.
    It's been a while since I was involved in Lime mortar but check out the websites for Mike Wye or Ecomerchant as they have plenty of information. Not sure of suppliers in your area but you may find something on the AECB (Association of Environmentally Conscious Builders - I think) website.
     
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  4. Gritineye Member

    Messages:
    603
    Sussex UK
    Trowelled lime mortar indoors will dry very white, and will not weather down to the mellow colour it does outside.

    To get over this the joints can be rubbed with an old towel when they've firmed off and dry, this exposes the aggregate and looks better.
     
  5. pedrobedro

    pedrobedro Man at Matalan

    Messages:
    8,325
    Location:
    CX Derbyshire
    What kind of reclaimed bricks ? If they are the old hand made uneven bricks our house is built with it was something like slaked lime and sharp sand originally used. I would use ordinary mortar with a light coloured sand and make the pointing a feature working with something I am familiar with rather than entering unknown territory.
     
  6. mangocrazy

    mangocrazy Italian V-twin nutjob

    Messages:
    461
    Location:
    Sheffield, UK
    This lime mortar thing confuses me. I'm aware there are at least two types of lime (possibly more), but the only type I'm familiar with and have used is what the French call 'Chaux' (or chalk). This is used routinely in the South of France in renders and mortars because of its toleration of extremes of temperature. We use it in a 1-1-6 mix (cement,chaux,sand) in both render and mortar. The only difference is the kind of sand used. I actually brought a bag of chaux back with me to use in mortar for a garden wall I'm planning to build next year. The chaux gives the mortar a very nice plasticity, resists cracking and being white gives a pleasant light-coloured mortar.
     
  7. Gritineye Member

    Messages:
    603
    Sussex UK
    That's the mix we used here before plasticisers where invented, nice smooth mortar and less brittle when set.
     
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  8. dobbslc

    dobbslc Member

    Messages:
    2,455
    Location:
    Hertfordshire UK
    Great advice chaps!
    I can get a bag of 3.5 lime morter from Travis Perkins for about £20 on the way home tonight. I'm after a whiter finish so this should do fine, the sharp sand will also give a more course finish but the sounds of it.
    I've got all the gear but no idea!:D
    I might do a "build thread" on this if anyone's interested???
     
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  9. slim_boy_fat

    slim_boy_fat Forum Supporter

    Go for it :thumbup:
     
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  10. gaz1 Member

    Messages:
    3,820
    Location:
    westyorkshire
    or post it in this one then we all can see the outcome of it
     
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  11. MrFluffy

    MrFluffy Member

    Messages:
    2,964
    Location:
    Rural France
    The best property of chaux blanc is the resulting mix is breathable and self healing to a extent if it cracks (plasticity as you say). As most of the older houses in France are made from mud/straw gluing stone together with a rendering over the top to stop weather washing the mix away, the chaux lets the underlying surface breathe and sweat a little so it doesnt get too damp, yet protects the original material, and when you get the inevitable settlement cracks because of no foundations etc its not such a big thing as it would be with a block/cement wall.
    Whenever I've used it, I just used chaux blanc and sharp sand, no cement in it.

    Edit, found a piccy of a classic french stone wall construction showing the layers. Hard work with a stihl saw cutting windows in, so was better for me to pick through completely with a pinch bar, then take a mass out and recast a lintel above the opening and build back up to restore strength.
    [​IMG]
     
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  12. Bryan Williams

    Bryan Williams Member

    Messages:
    135
    Location:
    Manchester England
    Just a slightly off topic brickwork tale...as a lad in seventies i was working in a house in Buckley North Wales. I mentioned it to my dad,an old school brickie,he asked if there was a mound at the bottom of the garden, I asked why and he told me that Buckley clay was so good and available that the first thing that the labourers did was make a small kiln on site and dig clay to make rough inner cavity bricks.Next day I checked,sure enough there were little bumps at the bottom of a few gardens, the homeowners didn't have a clue about them just made rockeries out of them.He said very often when he halved a rough brick there would be a big pepple in it.
     
  13. mrfuzzy

    mrfuzzy Forum Supporter

    Messages:
    8,629
    Location:
    Kirriemuir, Angus, Scotland
    You could also use snowcrete and building sand, poss be easier to work with and give you a nice light colour also
     
  14. mcostello

    mcostello Member

    Messages:
    425
    Lancaster, Ohio
    Is mortar that the user mixes with lime at home the same thing You are talking about? FIL used it and said it lasted forever.
     
  15. julianf

    julianf Member

    Messages:
    2,538
    Location:
    devon, uk
    Don't let Travis stiff you too bad on the cost.
    I'm about to order 7 bags, and the price is 9.50 ex. Mike wye would be 8.75 ex.


    I was doing NHL work yesterday. Finished colour is lighter than the sand, but not by loads and loads. The sharp I use is very red, and the dry product is similar tone to standard gypsum plaster.

    I'll see if I can't post a photo later.
     
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  16. armalites Member

    Messages:
    1,856
    Herefordshire
    It is the wrong time of year for using lime putty mortar but it would be fine inside as long as there is no heating and it's not too dry in there.

    There is a huge amount of misunderstanding about traditional lime products.

    I've done a couple of courses with these guys and they know their stuff

    https://www.lime.org.uk/
     
  17. julianf

    julianf Member

    Messages:
    2,538
    Location:
    devon, uk
    I realise i have a couple of photos up here anyhow -

    [​IMG]

    The lumps under the slate are nhl and sharp sand.

    Also this wall, but it was probably still a bit damp in the photo (so a bit darker) -

    [​IMG]



    I would say it depends more on the sand used really. Sharp sand in our area is very red. If you were to use yellow sharp, the mortar would turn out way lighter, and less pink. Use cornish grey sharp, and it will turn out light grey.

    Lime putty always seems to be less coloured though. The original stone work here would have been putty, not NHL, and the mortar varies from light yellow, to off white grey. Its much softer, and less like concrete than NHL.

    NHL is stickier than cement. Putty is nicer to work with again, but the price and availability is so much greater.
     
  18. julianf

    julianf Member

    Messages:
    2,538
    Location:
    devon, uk
    ratio -

    I end up using 3:1 for most stuff. Im not a pro with lime though - i just make it up as i go along, and it seems to work out.

    I guess for a softer brick wall, you may want to go to a lower quantity of lime, but, if its just a bit of internal pointing, its not going to matter really.

    3:1 gives a fairly course end finish with sharp sand. If you want a smother finish, you could up the lime, or add a touch of soft sand (if your sharp is as course as mine), given that, really, it seems that its a cosmetic goal you are after, rather than something that is structurally critical.
     
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  19. dobbslc

    dobbslc Member

    Messages:
    2,455
    Location:
    Hertfordshire UK
    Well as requested here's the start of the fireplace rebuild....
    This is how it looked when we moved in.
    IMAG3277.jpg
    Crappy Machine Mart burner badly fitted and condemned!
    The flu was half full of crap on the 90° bend when I took it out!

    After a bit of crowbar and hammer action!
    The opening was too small for the 5kw burner we wanted so it needed widening and the lintel lifting a couple of courses.

    IMAG3404.jpg

    IMAG3403.jpg

    Hole made to take the needle prop needed to support the chimney breast.

    IMAG3409.jpg

    I got lucky on eBay and found two short acrow props nearby for £20.:laughing:
     
  20. fizzy Member

    Messages:
    1,351
    uk
    We have shipped loads of pallets of plaster to France for our customers. They get British plasterers/builders over to do their houses and they just can't work with the French stuff!
     
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