Grade II listed - what repairs are allowed?

[YAPH]

Thanks Anna, and everyone. I phoned Mr & Mrs Owner[1] this morning with gist of your contributions and Mrs O phoned CO uttering Magic Words[2] who agreed to stack being rebuilt pronto with that and original-type bricks. Bobski went off to source reclaimed bricks (originals falling apart, hence problem with stack) whilst Mrs O phoned round & found a supplier for for HLM & sent builder off to fetch that, plus supplier offered to give builder a quick crib on how to use the stuff. Talking of which any gotchas to using lime mortar? ISTR Anna writing at length about it some time back but it doesn't seem to have found its way onto our wiki.

[1] currently off-interweb until formerly wirus-ridden Windoze PC, now newly linuxified[3], gets back to them [2] "Hydraulic Lime Mortar" [3] The machine was practically old enought to be listed itself: you can just see it, can't you? "That PC originally had Microsoft Windows on it, so you've got to remove Linux and restore it to its original state" :-)

[george (dicegeorge)]

Talking of which any gotchas

isnt it too cold for lime mortar, it doesnt set properly in freezing conditions?

32 page illustrated paperback offering sensible, easy-to-follow advice based on 25 thrifty years

of practical experience, for anyone wishing to repair, redecorate or maintain an old building in the traditional manner. Suppliers list updated annually. Over 13,000 copies sold.

£4.00 per copy in UK (including post & packing), £30 for 10 copies. £5.00 (sterling only) per copy overseas.

[g]

[chris French]

See, they can be quite reasonable :-)

Worth checking that the mortar will match the existing mortar colour (it can be quite variable)

It may want protecting at this time of year from frost/cold winds or heavy rain. esp in an exposed location such as a chimney stack

[meow2222]

Non-hydraulic lime needs to be treated differently to cement, or bad things can happen. But hydraulic lime sets like cement - albeit softer

- and can be used much the same way as cement. I guess its still wise to cover it in this weather though for a few days until its dried (dry does not equal set).

NT

[Anna Kettle]

Make a hydaulic lime mortar mix with the same aggregate and proportions that he would do using cement

Technique is much the same as with cement but it will take longer to set and should be protected with hessian (which has just the right amount of permeability) for as long as possible. At least a week, preferably three at this time of year

The colour wont match, it will be far too white but do a sand colour match as well as can be managed and over the next couple of years lichen will get a hold and the new work will mellow to match the old

Someone else wrote a good summary ages ago which was on the FAQ. I tend to write regularly but not at length

Anna

[The Natural Philosopher]

If the listing people had been around in the Dark Ages we would still be living in saxon wattle huts...

[unopened]

Err - no. If the *planning* people had been around in the Dark Ages we would still be living in saxon wattle huts. If the listing people had been around in the Dark Ages we would still have lots of examples of saxon wattle huts, all completely original in the same way that the philosopher's axe remained the same axe, as well lots of new build in exciting new styles.

Sid

[Bruce]

Painting the mortar with a thin coat of live yoghurt will help speed this process. Wait for the mortar to cure before doing it - probably four to six weeks at this time of the year.

It must be *live* yoghurt.

[Maris]

Having worked for a local authority architect's department at a low point in my life I recognise the scenario. I was converting a garage in a council estate into a bedroom for a disabled person (high point of my architectural career!) I seem to recall lots of conflicting requirements between various council bodies but no system in place to give an indication of whose requirements had priority. At this point I gave up my architectural career and went into computers! Maris

[Hugo Nebula]

On Tue, 27 Jan 2009 09:25:03 +0000, a certain chimpanzee, The Natural Philosopher randomly hit the keyboard and produced:

Hate to say it, but the one wearing the safety sandals was correct. The building regulations would have only applied to a *replacement* stair, and then only if there was other work to the building that was 'relevant'.

[The Natural Philosopher]

Oh I know that the listing people were in fact correct. The house could not have passed building regs as a new build at all.

I just wanted to point out the tussles you can get into if you start 'replacing' rather than 'repairing'

[Appin]

The message from [e-mail] (Anna Kettle) contains these words:

Current thinking is that hydraulic lime mortar isn't the complete answer. Mixture of lime putty and hydraulic lime mortar to ensure that there's a both good initial set and long term stregth.

[Appin]

The message

from [e-mail] contains these words:

One point being missed here is that the chances are that a chimney stack will have received some less than sympathetic attention in the past half century and so have a fair bit of cement pointing. That will mean it's not "like for like" which may be required, but the use of materials identical to the original.

[The Natural Philosopher]

My builders aid that if you used white cement and a bit of lime as well, chances are the conservation people wouldn't notice anyway..

But beware of strong repairs on weak bricks held togeher with existing weak mortars.

You may just create a new problem further down..

[george (dicegeorge)]

The booklet which I have bought via amazon Lime in Building by Jane Schofield

says not to mix portland cement and lime, that removing any portland cement which may have been used to patch your chimney decades ago is a hard job, and that lime takes many weeks to dry, during which time it must be protected from frost, so if it's protected by sacking would you have to have the scaffold up for a month?

the best time is late spring.

why not get the booklet?

[george (dicegeorge)]

Mortars and Renders: The Relative Merits of Adding Cement

Graham O'Hare

For many years those specialising in historic building repairs have known the dangers of using hard, cementbased mortars. But the specialist world has been split between those who advocated the use of small amounts of Portland cement as an additive to a lime mortar and those who rejected all cement additives. New evidence sheds light on the controversy, with some radical conclusions.

[george (dicegeorge)]

My house is in an exposed area, should I use hydraulic lime or non-hydraulic lime? We recommend that for external rendering and pointing hydraulic lime should be used. Are these products more expensive than conventional modern cements and plasters? Yes, but less expensive than using inappropriate materials that will harm your building in the long term