Lime mortar query

[Cornishcottage_]

Quote

Remove all existing cement render and remove from site, rack out brick work to 10/15mm , apply DG27 breathable primer, followed with 3 coats lime mortar with fibres and a smooth finish. Total 24,000
west gable only. Process as above 8,000.

Confused with
1) DG27 primer - is this a good idea?
2) l need to clarify “lime mortar” it’s an historic brick house 1904. Hydraulic lime or putty?
3). The area is a total of 180 square meters is that a reasonable quote?

 

[RBailey]

1) It would be a no to DG27 from me, a good wetting down (or two) which has been allowed to soak in is all you should need.

2) Naturally Hydraulic Lime (NHL) is now being found over time to go much harder than thought and it can crack / damage bricks so is not popular with conservators. However, as it is much more like Ordinary Portland Cement (mix dry, sets up quickly), builders like it as they can still claim to be using lime. Putty or hot lime is the more traditional and better method and gives a much "softer" / flexible result.

3) Cost, sorry can't help, I do it all myself.

I'd recommend this booklet on lime, a good background and only a fiver.

Lime in Building - A Practical Guide by Jane Schofield

If you want to use lime to repair or redecorate an old or natural building but are unsure where to start or what to do, then this booklet is for...

www.blackdogpress.co.uk

Cheers,
Richard B.

 

[Cornishcottage_]

Thank you Richard much appreciated

 

[Lacan07]

Quote

Remove all existing cement render and remove from site, rack out brick work to 10/15mm , apply DG27 breathable primer, followed with 3 coats lime mortar with fibres and a smooth finish. Total 24,000
west gable only. Process as above 8,000.

Confused with
1) DG27 primer - is this a good idea?
2) l need to clarify “lime mortar” it’s an historic brick house 1904. Hydraulic lime or putty?
3). The area is a total of 180 square meters is that a reasonable quote?

Is this to re-render an external wall or to repoint?

 

[Kearn]

Quote

Remove all existing cement render and remove from site, rack out brick work to 10/15mm , apply DG27 breathable primer, followed with 3 coats lime mortar with fibres and a smooth finish. Total 24,000
west gable only. Process as above 8,000.

Confused with
1) DG27 primer - is this a good idea?
2) l need to clarify “lime mortar” it’s an historic brick house 1904. Hydraulic lime or putty?
3). The area is a total of 180 square meters is that a reasonable quote?

Leave the DG27 alone. It’s unnecessary, sadly a genuine plasterer should know that.
It’s a lime render, not a mortar as they aren’t repointing - picky I know, but again they should know their craft and have some attention to detail! Putty.
Pricing for 3 coat alone, ranges from
£120-180/m2. However, the removal of the existing render and raking out won’t be included in that range. These can both be a pig of a task, and need to be done with enough care to not damage the remaining structure, so assume they’ve over estimated here for worst case. These bits can also be DIY easily enough which will save easy cash.

 

[MatthewC]

As I recall, we used DG27 when (for instance) repairing lime plaster (on lath) when some of the wall is OK and some plaster had to be removed entirely. Thus we repaired the missing stuff and applied DG27 to the old, then did the final skim over both old and new - hence I still cannot see the join. Also, if you want lime on plasterboard, it helps the lime to stick!