Old (old) house mortar is shot in many places, replace with?

[purplemonkey]

hi,

I've got this house, its 150-400 years old in different places. one of the oldish bits has terrible condition brickwork, you can pull the bricks out by hand and the mortar just blows away. I've been replacing it all so far with a standard cement/home sand/yellow sand mix. I just want to know if I should continue doing it this way or switch to a lime mix? I'm also wondering how to finish the walls i.e. plaster/plasterboard but I do not want moisture to ruin it all. most of the brickwork is single skin. should I batten (with dpc behind) then screw plasterboard on. or can I plaster (sand/cement) direct to the brick, or in this case should I be using lime?

sorry basic questions, but I need to start somewhere.
thanks.

 

[tony1851]

As parts are so old, is it listed?
If so, you should be speaking to the local authority conservation officer.

 

[pinenot]

NEVER EVER, fix/patch or re-point an old building (pre 1940ish ) with cement mortar/ mix, this traps in moisture in a building that was designed to breath moisture.

Sorry for the rant, but it's true, buildings up to the 1940's were built with lime mortar, these was weaker than the bricks or stone used in the building and allowed any moisture to wick out of the wall matrix an evaporate. Cement mortar is waterproof and is used in buildings of a very different design.

Buildings of these older decades were invariably built with open fires, as their sole means of heating, this was accompanied with drafts from windows and doors etc. and vents in the stone/brickwork, this of course was good as it provided positive ventilation or air circulation as it was described then. We, the collective we that is, have forgotten how to build like this for the most part, preferring rather builds that rely on strength and withstanding the elements rather than builds that accommodate them...pinenot

Oh! I'm a rootin tootin unbearable master, ain't I

 

[purplemonkey]

thanks pinenot, guess I need to look into this lime mortar mix then!

your comment about open fires is interesting because all our fireplaces are bricked up, we are looking to put in a combi boiler and radiators so I hope this wont be to much of an issue.

so assuming I go ahead and repoint with lime mortar and all my brick work is lovely once again, whats the best way to finish the walls. considering I'd like to include insulation. We have to lime plaster some walls, but we are open to use what we like on others. Is it as simple as battens and plasterboard (with 25mm air gap, 25-50mm insulation in the batten cavity)?

thanks.

 

[purplemonkey]

oh I forgot one point, is this lime mortar case the same even with internal/party walls?

 

[tony1851]

purplemonkey;
Your posts suggest you really need to get proper advice on this before you do anything.

 

[pinenot]

Yes, the point is not to change anything in the wall build, that way it functions in the same way as it was designed to.

Re properly advised, there are few remaining builders outside conservation specialists to choose from, there are like myself, some sustainability qualified bods out there but getting contact with them is another matter. There are many many so called experts out there advertising their wares, you just have to check this sites archives where so many people post asking advice as to how they can rectify the mess left by said so called experts. Help is at hand though, it's called the internet where such bodies as www.buildingconservation.com/articles - historic scotland lime mortar articles, of which this may be of intrest : http://www.historic-scotland.gov.uk/informguide-limeandcement.pdf. as far as how to insulate traditional built superstructures, that's a little more complex than you would think, have a look at this - http://www.lime.org.uk/directlinkdownloads/10226Ty-Mawr_lime_hemp.pdf

This is a fascinating and ever increasing section of the build environment , offering many solutions to both traditional build and today's day to day problems...pinenot

 

[tony1851]

All this is a waste of time.

If the OPs house is in this country and 150-400 years old, it is almost certainly listed, in which case no work can be done without local authority approval.
He needs to speak to the local conservation officer first.

 

[purplemonkey]

hi pinenot, funny I was just reading about lime-hemp-plaster, I'm going to speak the chaps at http://www.lime.org.uk/ next week as they appear to have all the products I will require. Just need to understand which ones i need.

this whole listed/old building thing is a pain in the rear for sure, and appears to be a licence to print money for some, but it looks like there is support out there. thankfully I live in the age of the internet and helpful people like yourself exist. cheers.

 

[pinenot]

Boll*?!s tony, your making wild assumptions - re listed - who has said this? apart from yourself - and a great deal of work can indeed be done to listed buildings, I should know I owned one "A" listed in parts "B" listed otherwise, over 400 years old which I renovated. New wall plaster (lime) some strapped and plaster boarded - original walls all lath and plaster with horsehair strengthening.

Whist I appreciated your fears, ask the questions first, gain the facts with some aplomb ...pinenot

 

[tony1851]

Boll*?!s tony, your making wild assumptions - re listed - who has said this? apart from yourself )

From the legislation;


Restriction on works affecting listed buildings.

Subject to the following provisions of this Act, no person shall execute or cause to be executed any works for the demolition of a listed building or for its alteration or extension in any manner which would affect its character as a building of special architectural or historic interest, unless the works are authorised.


Offences;

(1)If a person contravenes section 7 he shall be guilty of an offence.
(2)Without prejudice to subsection (1), if a person executing or causing to be executed any works in relation to a listed building under a listed building consent fails to comply with any condition attached to the consent, he shall be guilty of an offence

 

[joe-90]

hi pinenot, funny I was just reading about lime-hemp-plaster, I'm going to speak the chaps at http://www.lime.org.uk/ next week as they appear to have all the products I will require. Just need to understand which ones i need.

Well fancy that - he's started posting links to another forum.

 

[Zebra579]

Mine is 400 years old and not listed. Being old doesn't necessarily qualify them for listing.
Yes, speak to lime.org, they are very good.
Definately don't use cement on old bricks, not just because of moisture and breathability as mentioned above, but because as the house shifts about as they invariably do when they're that age, being built with little in the way of foundations, then the mortar will allow for that bit of movement without cracking both itself and the bricks.

 

[joe-90]

Speak to these people, they are brilliant.

http://www.lime.org.uk/

Why are you both here?

You can get all the advice you need at:


http://www.lime.org.uk/

They are brilliant at http://www.lime.org.uk/

Fantastic people at http://www.lime.org.uk/

 

[purplemonkey]

joe, what the hell are you going on about?

pine has been really helpful providing truly useful information, he hasn't judged my question in any way unlike some, and has in no way promoted or singled out any company/forum. the website/company at lime.org looks like a great range of products for historic buildings, can't find another good alternative anywhere. So I've no idea why you are taking the pi**.

Pine. I also recently just read about the movement problem re: cement, so yeah another good reason to go lime.

I think this thread is finished now. but I will be back with more questions as I have a ton of work to do on this building

good to know some people are helpful and these forms can be useful.