annie Posted April 23, 2012 Share Posted April 23, 2012 Am having problems getting right mix for internal stonework - we are in aquitaine - need a light mix - can anyone help please? Link to comment Share on other sites More sharing options...
Théière Posted April 23, 2012 Share Posted April 23, 2012 The colour comes primarily from the sand you use, washed river sand is generally lighter so produces a lighter finished result. Mixing a 2:1 sand/chaux mix should suffice. Link to comment Share on other sites More sharing options...
Dave&Olive Posted April 23, 2012 Share Posted April 23, 2012 Hi Ok I find Renocal mixed 3.5 / 1 will give you a better finish than just pure lime ...the colour is dictated by the sand unless you fork out for the pre mixed stuff [IMG]http://i83.photobucket.com/albums/j311/daveolive/render/PDR_0110.jpg[/IMG] Dave Link to comment Share on other sites More sharing options...
Théière Posted April 23, 2012 Share Posted April 23, 2012 Hi not ok,Renocal = 2/3 chaux + 1/3 ciment the expensive way and gives you a worse mix of both worlds don't use it.I could spend an entire evening finding loads of links to Not add ciment to chaux........http://www.lime-mortars.co.uk/articles/cement-and-lime-mortar Link to comment Share on other sites More sharing options...
Dave&Olive Posted April 23, 2012 Share Posted April 23, 2012 [quote user="Théière"] Hi not ok,Renocal = 2/3 chaux + 1/3 ciment the expensive way and gives you a worse mix of both worlds don't use it.I could spend an entire evening finding loads of links to Not add ciment to chaux........http://www.lime-mortars.co.uk/articles/cement-and-lime-mortar [/quote] Hi Ok With only 42 years of working with Welsh stone buildings and only 7 years with French ones I kowtow to your knowledge Dave Link to comment Share on other sites More sharing options...
Théière Posted April 23, 2012 Share Posted April 23, 2012 Not getting it right after 49 years "experience " is certainly something.I was trained properly and commenced doing it right from day one.[:P]http://www.buildingconservation.com/articles/cement/cement.htm Link to comment Share on other sites More sharing options...
Dave&Olive Posted April 24, 2012 Share Posted April 24, 2012 hi ok I agree I came over by Plane so unlike you I missed the training on the Ferry coming over Dave Link to comment Share on other sites More sharing options...
Russethouse Posted April 24, 2012 Share Posted April 24, 2012 Interesting though your past lives may be, the ******* contest isn't helping the OP! Link to comment Share on other sites More sharing options...
sid Posted April 24, 2012 Share Posted April 24, 2012 I use Renocal, mixed at between 2:1 and 3:1 depending on exactly what aspect of the finish I'm aiming for. The less sand the whiter the finish, but I prefer a more off-white/creamy look. The product is on the list of recommended mortars specifically intended for the restoration of old buildings, national treasures. It was recommended to me by my own builder. It is expensive but I find it very easy to work with as it has a plasticiser added, so it's ideal for a dedicated amateur like myself. To sum up, if it's used by the local French artisans, it's good enough for me. If I didn't do the job myself but got someone else to do my pointing the odds are that I'd get the same product applied anyway. Link to comment Share on other sites More sharing options...
pachapapa Posted April 24, 2012 Share Posted April 24, 2012 Of course, renocal is popular in deux sèvres due to its promotion by the large Calcia Italcementi operation at Airvault.But any company producing chaux products with an italian background is bound to be good.Renocal is a good product for inexperienced artisans and amateur chaux enthusiasts and will give good to excellent results even for a neophyte.http://goo.gl/k80d5http://www.ciments-calcia.fr/NR/rdonlyres/AEDBD14C-90A1-4AAD-B969-35430058E3C7/0/Chaux.pdfDepending on use I will use products produced by Calcia, Lafarge and St Astier as suitable.I have just completed some 100 m2 of internal pointing and enduit in a 17th century barn and for this I used exclusively a St Astier Tradilege Natural Hydraulic Chaux mainly because at Leclerc in parthenay it was almost € 4 a pocket cheaper than similar products from Calcia and Lafarge.As to colour there are two possibilities, one to add a natural earth colorant to the mix when the colour of the sand is of little effect or to lift the "laitance" gently from the surface just before the initial "prise", either with a soft brush or a sponge, to reveal the natural colour of the sand contained in the mix.Sand colours will depend on the local supply but for example, sand from la loire is light coloured, sand from la vienne is slightly yellower, sand from the cher is beginning to have a slight reddish tinge. A sand with a granulometric size range les than 2mm will be more amenable to a common 2-4mm size range. Do not use under any circumstances that which is called a "sharp" sand. Link to comment Share on other sites More sharing options...
BIG MAC Posted April 27, 2012 Share Posted April 27, 2012 Hi Pacha, I am intrigued as I would have imagined that coarse / sharp sand would have been what was used in the construction of our buildings...certainly the the mortar where it has dislodged is very 'gritty' and I would have imagined sharp sand would have lent more 'body' to the mix?Are you recommending 'soft' sand and if so why?Cheers...Mac Link to comment Share on other sites More sharing options...
Dave&Olive Posted April 28, 2012 Share Posted April 28, 2012 Hi Ok the size of the sand should be a % of the gap you are trying to fill . Dave Link to comment Share on other sites More sharing options...
pachapapa Posted April 28, 2012 Share Posted April 28, 2012 Hi not OkSo what was the variability in the grade of your sand purchases in relation to the rather variable gaps which you have tried to fill in the picture below?[IMG]http://i83.photobucket.com/albums/j311/daveolive/render/PDR_0110.jpg[/IMG] Link to comment Share on other sites More sharing options...
pachapapa Posted April 28, 2012 Share Posted April 28, 2012 [quote user="BIG MAC"]Hi Pacha, I am intrigued as I would have imagined that coarse / sharp sand would have been what was used in the construction of our buildings...certainly the the mortar where it has dislodged is very 'gritty' and I would have imagined sharp sand would have lent more 'body' to the mix?Are you recommending 'soft' sand and if so why?Cheers...Mac[/quote]By sharp sand I was thinking of something like this[IMG]http://www.wickes.co.uk/content/ebiz/wickes/invt/220112/Sharp-Sand_medium.jpg[/IMG]The OP with internal work is likely to be doing "pierre apparente" rather than "rejointement" ( pointing in english). Where you live the local available stone tends to be schist with its longest dimension laid horizontal and a repointing technique will be used. Other areas of france have for example in La Vienne a tufaceous rock which is laid similar to schist but the repointing is done with a local clay with the material between the stones left some 2 cms from the outer surface to protect it from the rain. The "moellons" of deux sèvres are irregular in shape and irregular in size and lend themselves to a "pierre apparente" technique where the smaller stones are concealed allowing the larger more aesthetically pleasing stones to stand out. Any attempt to point this irregular material results in a fussy christmas pudding texture to the wall. The core material of a wall varies from a clay to a clay-sand-lime mixture. The quality of the lime used is very variable as it was made in a simple vertical lime kiln with charcoal; often the slaking process on site was very rudimentary. Link to comment Share on other sites More sharing options...
Dave&Olive Posted April 28, 2012 Share Posted April 28, 2012 Hi ok Failing to find a Wicks in France I tend to use 0-2 for the render and 0-8 for the pointing ,you can the sieve out the larger stone for the pointing .... Dave [IMG]http://i83.photobucket.com/albums/j311/daveolive/P1000283.jpg[/IMG] Link to comment Share on other sites More sharing options...
Théière Posted April 28, 2012 Share Posted April 28, 2012 [quote user="BIG MAC"]Hi Pacha, I am intrigued as I would have imagined that coarse / sharp sand would have been what was used in the construction of our buildings...certainly the the mortar where it has dislodged is very 'gritty' and I would have imagined sharp sand would have lent more 'body' to the mix?Are you recommending 'soft' sand and if so why?Cheers...Mac[/quote]Pointing/building with lime requires a good mix of sand to produce the strongest yet flexible mix, sharp sand is one of the constituents but by itself hasn't enough fines to produce the best work. Link to comment Share on other sites More sharing options...
BIG MAC Posted May 15, 2012 Share Posted May 15, 2012 That's what I thought Theiere....I would have thought that small stones would have been wedged in the larger gaps and the 'pointing' flushed over much the same as in the UK. The stones employed in this way provide a mechanical strength not achievable in a lime mortar alone. Cheers Link to comment Share on other sites More sharing options...
sid Posted May 16, 2012 Share Posted May 16, 2012 Post removed , I'm only going to get into an argument again. Link to comment Share on other sites More sharing options...
Théière Posted May 16, 2012 Share Posted May 16, 2012 No your not![;-)] Link to comment Share on other sites More sharing options...
BIG MAC Posted May 16, 2012 Share Posted May 16, 2012 Mortar the point did I get something wrong? Link to comment Share on other sites More sharing options...
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