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Posted: Thu Aug 06, 2015 8:56 pm
by Grahamh8
I believe the ratio of 3:1 sand:cement is generally used for pointing.
Could somebody let me know if this is suitable for Indian sandstone? Is the sand, sharp or builders sand and should I add SBR to the mix?
Posted: Sun Aug 09, 2015 3:44 pm
by Grahamh8
Any suggestions?
Posted: Sun Aug 09, 2015 7:01 pm
by dig dug dan
Sand and cement has always failed me over the years, no matter what mix.
use easipoint or easijoint, one can be aplied in the rain, the other cannot!
both of those have been recieved critical acclaim, unlike geofix!
Posted: Sun Aug 09, 2015 9:36 pm
by lutonlagerlout
plastering sand gives a technically stronger joint but a coarser finish
building sand has been used for years but is weaker
the key is to make the mix the right consistency so it does not stain the flags
wet enough so it bonds, but not so dry it does not set right
weatherpoint 365 is a decent polymeric which guarantees no staining and can be installed in the rain
cheers LLL
Posted: Sun Aug 09, 2015 10:40 pm
by Grahamh8
lutonlagerlout wrote:plastering sand gives a technically stronger joint but a coarser finish
building sand has been used for years but is weaker
the key is to make the mix the right consistency so it does not stain the flags
wet enough so it bonds, but not so dry it does not set right
weatherpoint 365 is a decent polymeric which guarantees no staining and can be installed in the rain
cheers LLL
Thanks alot, and SBR does it improve the mix at all?
Posted: Mon Aug 10, 2015 6:48 am
by Mikey_C
yes, but increases the risk of staining
Posted: Sat Aug 22, 2015 3:51 pm
by Grahamh8
So 3:1sharp sand to cement, plus a small amount of SBR, is suitable for pointing? If I'm going down the mortar route and have some larger joints ie 15mm.
Should the slabs be wetted before hand and the surface be allowed to dry? I'm planning on a semi moist slump and hand pointing, striking off with a pointing iron.
I'm sure my main issue will be staining of the limestone.
Would washing off with a wet sponge immediately, minimise this?
Posted: Sat Aug 22, 2015 5:05 pm
by seanandruby
I usually adopt the saturated surface dry procedure
Posted: Sun Aug 23, 2015 10:54 am
by sy76uk
We all have different ways of pointing.
The thing we all have in common is that we all use at least a 4/1 mix (I use 3/1) we do out best to keep surface staining to a minimum and if there is any then it will be temporary so nothing that will need a wire brush of chisel to remove ounce cured.
Pointing well for me is on of the hardest jobs to get right and the only way to get it right is through trial and error and finding the way that suits you best.
I like to use a mix of plastering and building sand mixed to a doe like consistency when Trowelling in.
Dampen joints beforehand if trying this method.
Posted: Sun Aug 23, 2015 2:29 pm
by Grahamh8
sy76uk wrote:We all have different ways of pointing.
The thing we all have in common is that we all use at least a 4/1 mix (I use 3/1) we do out best to keep surface staining to a minimum and if there is any then it will be temporary so nothing that will need a wire brush of chisel to remove ounce cured.
Pointing well for me is on of the hardest jobs to get right and the only way to get it right is through trial and error and finding the way that suits you best.
I like to use a mix of plastering and building sand mixed to a doe like consistency when Trowelling in.
Dampen joints beforehand if trying this method.
Thank you for the info. Would sharp sand be too coarse and what about SBR? is that overkill?
Posted: Sun Aug 23, 2015 9:54 pm
by sy76uk
I personally never use SBR in pointing.
Sharp sand will give a very strong joint but is very hard too work with.