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Posted: Mon Sep 10, 2012 7:09 am
by glenne_n
OK guys,
I thought you added it to the mortar as a plasticiser/waterproofer.
It's relatively expensive stuff. The instructions implies undiluted to 2:1. Think 2:1 is adequate for the coping on my raised planter beds.
Posted: Tue Sep 11, 2012 1:26 pm
by glenne_n
Hi Guys,
All information received so far is highly valued, I stiil have a problem, however.
I've purchased Cementone SBR £18 for 5 ltr. Quite expensive stuff compared to other offerings, remember I'm not a pro but an average DIYer.
Do I need to use SBR for 600x280 coping for 20M of raised plant bed wall. Is there anything else that would be less complicated but effective.
I was looking for an additive to the mortar mix (or water), if SBR is still recommended would this be enough using a 5:1 water SBR mix as suggested by LLL.
Posted: Tue Sep 11, 2012 2:13 pm
by lutonlagerlout
prime the copings with it and add it to the water
i was using SBR yesterday
it does the job long term
that is how you should look at it
LLL
Posted: Wed Sep 12, 2012 1:08 pm
by glenne_n
Hi Guys,
Thanks for all your inputs, not everybody does things the same way and it is always good to hear the different opinions [from which I'll make an informed choice].
For your information, I contacted Cementone technical support and here was their advice for using SBR:
1 SBR:1 Water:5 OPC, apply to damp wall and coping.
1 Cement:2 Sharp sand:3 SBR:1 Water, apply to wall while slurry above is still wet and bed Coping.
Posted: Wed Sep 12, 2012 6:25 pm
by r896neo
I don't care what Cementone say, don't use sharp sand for copings.
Personally for pressed concrete copings i prime the coping with a 3:1 slurry (sbr:water) then i add about 100ml of sbr into a half bag of cement sized mix. For more porous non pressed concrete i just put it in the mix.
I along with everyone (apart from cementone's technical guy) lay them using building/soft sand.
Posted: Wed Sep 12, 2012 6:51 pm
by glenne_n
After reading the posts from you guys ans my own limited experience, was never going to use sharp sand.
Cementone, of course, want to sell as much of their product as possible (cynical me) hence the rich mixes of SBR.
I, as usual, will consider all the posts and settle with a compromise that i think is optimum.
Once again, I think this is a brilliant forum.
Posted: Wed Sep 12, 2012 7:26 pm
by lutonlagerlout
when i say sharp I mean plastering sand
it is much stronger than building sand
LLL
Posted: Thu Sep 20, 2012 12:14 pm
by simeonronacrete
For the optimum in terms of strength, adhesion, waterproof, frost resistance, freeze / thaw cycle resistance do the following:
Brush apply a primer (also called bond coat) of 1:1 Ronafix:cement to clean, damp substrate and back of clean damp coping. Before this dries mix the mortar.
Mortar is 1 volume cement, 2 parts medium sharp. The liquid is 3 parts Ronafix to 1 part clean water. add enough of the diluted Ronafix to the cement and sand to produce a workable mortar. Apply 6-12mm thick and bed coping on top. Compact into place.
Joints can be raked out and re-pointed with coloured mortar if you wish.
This method has been professional industry standard since the 1970's and is BBA Approved.
See
Ronafix for Brick Slips
Edited By simeonronacrete on 1348139690
Posted: Thu Sep 20, 2012 8:30 pm
by glenne_n
Well I've opened the SBR now, interesting the use sharp sand I was sure that buiding sand was the correct way to go after the other posts.
Haven't started the job yet but I have a tonne of sharp sand and a tonne of buiding (yellow) sand.
Looks like a flip of coin is in order here.
Would it br fair to say building sand for normal mortar for bricks but sharp sand when using SBR, Ronafix and the like for coping.
Posted: Thu Sep 20, 2012 9:05 pm
by local patios and driveway
Seriously, who here uses ronafix? What a crock
Posted: Thu Sep 20, 2012 9:36 pm
by lutonlagerlout
cookie uses it, and I have used it where specified.
its the best but with a price tag to suit
just because you haven't used it doesn't make it a *crock*
does it dan?
regards LLL
Posted: Thu Sep 20, 2012 9:57 pm
by local patios and driveway
Sbr does the job for far less.
Posted: Thu Sep 20, 2012 11:29 pm
by lutonlagerlout
its like comparing a BMW and a porsche dan
you cant really
if something is specified then we use it
architects tend to stick to what has worked for them in the past
LLL 
Posted: Fri Sep 21, 2012 7:05 am
by GB_Groundworks
When you are doing commercial jobs or working to an engineers spec you use it local, of you are laying a few flags inns back garden then no you don't. If you're bedding copers on the top of a flat roof parapet wall 5 stories up then you use ronafix if specified because if it comes loose it could kill someone, and you can't turn rd and say I knew better than the engineer because it was cheaper.....
Posted: Fri Sep 21, 2012 7:38 am
by local patios and driveway
Yeah ok i will accept if an engineer has speced it yes, but does this diy'er need it? No.
Will ronacrete take the chance to shamelessly plug themselves again? Yes.
Will they ever offer advice that doesnt include a plug? No.
I feel used and dirty when that guy comes online to post here.