Gervase
Member
- Messages
- 1,500
- Location
- North London
Personally, I'd only use NHL5 above ground on chimney caps and flaunching and to bed ridge tiles. It's far too cementitious for general use.
- Thread starter michael
- Start date
Nemesis
Member
- Messages
- 9,402
- Location
- Planet Earth
Yes. It's certainly a better option for modern building purposes than cement as it's more eco friendly, but I'd be very wary of using it for general pointing etc in a period building.
Even for chimneys (apart from flaunching) I think it's poss a bit OTT.
Even for chimneys (apart from flaunching) I think it's poss a bit OTT.
Do you all think I should use up my £15 a bag Hydraulic lime on my few bits of bricklaying as piper suggests or do you think I should discard it for cheap and cheerful hydrated? I have about 30 stretcher bricks to lay on the internal face of an external wall. The Hydraulic lime I have is HL2
Thanks everybody for your interest and thanks piper again for educating me
Thanks everybody for your interest and thanks piper again for educating me
biffvernon
Member
- Messages
- 4,607
- Location
- Lincolnshire
If you mix a bag of NHL 2 with a bag of hydrated you will get two bags of NHL 1. Kind of.
I think I would like to avoid mixing the two biff. I only require one bagful of lime and reading earlier postings about how the lime can go off in the bag, buying a bag of hydrated and opening both the hydrated and my existing hydraulic would be wasting a lot of lime.
As I said I only have to lay about 30 bricks so my options would seem to be:-
1.Keep Hydraulic lime unopened for use on another day. Buy a new bag of Hydrated lime, mix required amount with sand and water and discard the rest of the bag.
2.Keep Hydraulic lime unopened for use on another day. Buy a new bag of Hydrated lime. Buy a slaking bath. Slake entire 30kg bag of hydrated lime. Use what I need and then have this surplus to requirement bath of slaked lime getting under my feet for ever and a day (very little outside storage space)
3.Buy a 25kg bag of ready mixed lime putty and sand
4.Use my £15 a bag hl2 hydraulic lime with no further purchases required.
Option 4 would obviously be the ideal solution for me but would it be a detrimental option? If its absolutly necessary then I’ll buy either the dry hydrated and mix with sand or I'll buy the lime putty but I dont know if either of these options are absolutly necessary
As I said I only have to lay about 30 bricks so my options would seem to be:-
1.Keep Hydraulic lime unopened for use on another day. Buy a new bag of Hydrated lime, mix required amount with sand and water and discard the rest of the bag.
2.Keep Hydraulic lime unopened for use on another day. Buy a new bag of Hydrated lime. Buy a slaking bath. Slake entire 30kg bag of hydrated lime. Use what I need and then have this surplus to requirement bath of slaked lime getting under my feet for ever and a day (very little outside storage space)
3.Buy a 25kg bag of ready mixed lime putty and sand
4.Use my £15 a bag hl2 hydraulic lime with no further purchases required.
Option 4 would obviously be the ideal solution for me but would it be a detrimental option? If its absolutly necessary then I’ll buy either the dry hydrated and mix with sand or I'll buy the lime putty but I dont know if either of these options are absolutly necessary
Gervase
Member
- Messages
- 1,500
- Location
- North London
NHL2 is what one would call 'pretty damned moderately hydraulic' in the old nomeclature - go ahead, use it, and you'll like as not see no problems at all. Most of the post 1850 expansion of London was built with lime that would roughly work out at around NHL 1 to 1.5 ( from kilns in the Thames Valley and through the Goring Gap), while the bigger, posher buildings were often pointed or 'dressed' with blue lias lime which would equate to our modern NHL 2.5 (or even NHL5 in the case of 'high toast' limes such as those used by Smeaton for the Eddystone Light and for the big foundations of some of our Victorian 'grands projets'). And, in a previous archaeological incarnation, I can vouch for the fact that such works are hellish strong!
Nemesis
Member
- Messages
- 9,402
- Location
- Planet Earth
I think though it's horses for courses (groan) where lime is concerned.
Foundations and the Eddystone Light are one thing, but repointing soft historic brick or stone I'd still go for non-hydraulic, in the main.
London brick of the 19th century of course was much harder industrial stuff than that used in previous centuries. It also has to be said very little mortar was used to 'butter' between bricks in many buildings. Sadly, many re-pointing jobs in recent times have used hard cement pointing to cover the tiny gaps, with heaven knows what results in the future.
[Open Image] [Hosted by PhotoGalaxy.com]
http://www.eastherts.gov.uk/guidnote/brick_repointing/full_document.htm
Useful stuff in that document.
Interesting pictures in the gallery part of this site:
http://www.historicbrickpointing.co.uk/gallery.htm
And worth watching the movie clip about tuck pointing.
Foundations and the Eddystone Light are one thing, but repointing soft historic brick or stone I'd still go for non-hydraulic, in the main.
London brick of the 19th century of course was much harder industrial stuff than that used in previous centuries. It also has to be said very little mortar was used to 'butter' between bricks in many buildings. Sadly, many re-pointing jobs in recent times have used hard cement pointing to cover the tiny gaps, with heaven knows what results in the future.
[Open Image] [Hosted by PhotoGalaxy.com]
http://www.eastherts.gov.uk/guidnote/brick_repointing/full_document.htm
Useful stuff in that document.
Interesting pictures in the gallery part of this site:
http://www.historicbrickpointing.co.uk/gallery.htm
And worth watching the movie clip about tuck pointing.
Nemesis
Member
- Messages
- 9,402
- Location
- Planet Earth
A wee bit more about bricks and mortar:
http://www.buildingconservation.com/articles/brick/brickwork.html
http://www.buildingconservation.com/articles/brick/brickwork.html