Costs of replacing pebbledashing with lime render?

[Hatster]

We're just buying a lovely 17th century Grade II listed farmhouse. (You can see it on the Estate Agent's site here:
http://www.bidwells.co.uk/view_property.php?property_id=CAM070192&property_type=residential)

It's timber framed, and is suffering rather from damp. We, the current owners and the surveyors are all pretty sure that the pebble-dashing is making things worse - it's a cement rich render, and cracked and repaired in a few places. The current owner would have loved to have removed the pebble-dashing and replaced it with a lime render, but felt it would have needed a lottery win to afford it! As you can see from the pictures, the house covers a pretty big area (it has a total internal area of 254m2) but the roof comes down low, so it is mostly 1 1/2 storeys that needs rendering, except of course at the gable ends .

Does anyone have an idea what sort of figure it would cost to replace? Are we talking a lottery win of £25,000 or of £100,000 to afford it?

 

[DaveBrigg]

Wow - great house. The internal view of the living room was fascinating. Presumably that is an original external timber frame wall which has become internal after an extension and had the wattle and daub or brick infill removed. A sort of 17th C skeleton.
We have what I think is a little smaller farmhouse, with cement render on three sides. The conservation builders who replastered inside gave a quote for rendering in lime which I cannot remember precisely, but I think it was in the region of £6 000. Since then, I have taken off about half of the render myself, with a borrowed hammer drill. The biggest problems were what to do with heaps of cement rubble (luckily someone in the village is putting down a concrete floor in their barn and needs all the hardcore they can get) and repairing the damaged brickwork, some of which turned to powder when touched. The final cost of your work will depend on the state of the brickwork beneath - assuming that it is brick - and rectifying any other problems that may be revealed. Although it had been dry for a few days before our cement was removed, the bricks beneath were damp to the touch. It was great to see them slowly become lighter in colour as they dried.

We have been given a quote of £330 for a pallet of lime, and will need a few tons of sand to mix in for the mortar. The going rate for a lime plasterer seems to be about £200 a day. A labourer to do the mixing could be about half that. Scaffolding will probably also be needed, and could easily cost £1 000, although it's hard to judge how much you'll need.
I would guess that if you just ring the builders and say 'sort it' you would still be paying less than the lower of your guesses. If you source the materials yourself, and get someone local to recommend a plasterer with the relevant experience, it could be less still.
Hopefully one of the skilled builders on this forum will spot your thread and give a more accurate estimate.

 

[Nemesis]

However - once the cement is removed, you may find that it has caused damage to the timber frame from trapping damp, which could require considerable repair. Also - it looks from the pics to have very flat plaster and this may be gypsum, which could make the problem worse. You could be opening a can of worms, so do take care before rushing to exchange contracts.

The listing description has it as having 'rough cast render'. Have you discussed any removal with the local authority Conservation Officer?

http://www.imagesofengland.org.uk/details/default.aspx?pid=1&id=51189


I'd additionally check that alterations to things like windows and doors etc had Listed Building Consent - or you could be obliged to return them to what they were.

TL 35 NE TOFT COMBERTON ROAD (South Side) 8/162 No. 42 (Old Farm Farmhouse) GV II Farmhouse. Early C17 with later C17 additions. Timber-framed with roughcast render. Plain tile roofs. Red brick ridge stack and C20 gable end stack to right hand. One storey and attic. Three unit lobby entry plan with an additional wing to left hand and rear kitchen wing with gable end stack. ` Main entrance in angle with leanto porch, C19 four-panelled door, and two sixteen-paned hung sash windows with C19 panelled shutters to right hand; two casement dormer windows. One attic horizontal sliding sash window and two-light casement window to crosswing. Interior: exposed timber-frame and floor frames; rear kitchen hearth with baking oven. Fire insurance plaque in gable of cross wing. RCHM West Cambs., p210, mon. 5

Re the surveyors - are they 'general surveyors, or ones with specific expertise in historic buildings?

 

[christianb]

Hi Hatster,

First, I agree with Nemesis regarding consent and the like. That would certainly be the first port of call.

Second, being listed you could have all sorts of problems if a complete jobsworth starts telling you that any lime render you use should contain Ibex hairs, squirrel farts and have been matured for at least twenty years in a virgin's armpit.

If all is good to go and you don't have to comply with a conservation zealot, then there are a couple of points I'd suggest:

1. If you're going to remove the existing render yourself, do so from the bottom up. This reduces the risk of the building unzipping itself if the damn stuff is hiding a serious structural problem. Or, worse still, holding the building together.

2. For past projects where I've not been confined to using finest slaked lime putty, I've been able to create my own mix from either (a) NHL2 or (b) type-S hydrated lime for about 10% of the cost it would be from a heritage building suppliers. In fact, I can lime plaster a room at less cost to the owner than if they employed a standard plasterer.

3. You're very lucky to have such a beautiful building.

All the best with the work,

Christian

 

[Nemesis]

Given the fact some who post here are Conservation Officers with a great deal of expertise in historic buildings, I do feel that post is a spot insensitive.

http://www.breckland.gov.uk/timber_frame_advice_sheet.pdf

And the first thing to do, before any thought of what sort of render (which your Conservation Officer will probably be able to give some very sound advice about, and you will require LBC to remove what is there anyhow) is to have a proper assessment of the extent of any damage which may have been caused to the sole plate and the timber framing by the damp.

http://www.buildingconservation.com/articles/mortgage/mortgage.htm

http://www.midsuffolk.gov.uk/NR/rdonlyres/A2D066DC-7762-44EC-90DB-FB055A764671/0/PlastersandRenders.pdf

Not sure which local authority you come under, but you will find a great deal of helpful advice I am sure if you contact the historc buildings / conservation team:

http://www.scambs.gov.uk/Environment/Conservation/default.htm

http://www.cambridge.gov.uk/ccm/navigation/planning/conservation/


There are other posts on this site, showing the type and extent of damage which some have encountered. It could prove very messy and expensive indeed to rectify this - proceed with great caution.

Although in this case there is in all probability damp, can I ask what form this takes, how it shows internally?

 

[christianb]

Nemesis,

Given the fact some who post here are Conservation Officers with a great deal of expertise in historic buildings, I do feel that post is a spot insensitive

There are Conservation Officers of the pragmatic variety, and those of a more despotic bent - rather like building inspectors. I've encountered both, but am glad to say that the former far, far outweigh the latter.

Either way, we all enjoy this forum because of our interest, passion and (sometimes) experience in old buildings. This, of course, does not mean entire agreement on every moot point. T'would be dull otherwise!

Christian

 

[Nemesis]

Indeed, but at times the appropriate materials will be suggested and approved by the CO and even EH - so pointless flagging up problems which may not occur, and branding many people who post here 'conservation zealots'.

 

[Hatster]

Thanks so much for this useful advice! We've had a preliminary chat with the conservation officer over the phone and she seemed very helpful, so we'll arrange a time for her to come over and talk about various things that we'd like to do. Depending on what she says, we'll then get a specialist engineer out to have a look at what the state of the timber is, and whether it would be a mistake to try to get the render off.

The damp is not noticeable in most of the main house, but I believe had damaged the plaster slightly in a couple of places, which has now been repaired. The current owner tries to make sure that there's a constant heat in the house over winter and that it is reasonably ventilated in summer, which I think is the right thing? To be honest, I didn't notice the damp myself, but my father in law is a former planning inspector and noticed it straight away.

 

[Nemesis]

If you need some sound advice, try Stephen Boniface, Whitworth Co-Partnership.

 

[christianb]

branding many people who post here 'conservation zealots'

This I did not do. And nor was it intended.

I should, perhaps, expand upon the principle of my "contribution": providing the homeowner isn't put over a financial barrel through the demands of an authority (which can sometimes defy logic), the removal of the aforementioned pebbledashed render and its subsequent replacement with lime should not cost the earth. And nor should it - I'm right-royally hacked off when I see TV property program "experts" take a sharp intake of breath at the very mention of using lime plaster as if it were made from crushed emeralds.

Christian.

 

[Essex]

We had similar problem of cement render, house about 350sqm, but two complete stories. We had to repair a lot of the sole plates (rot under the cement render) and some of the verticals, particularly at the south west corner (prevailing wind), total cost about £60,000 including adding some brick walls with limecrete foundations under the sole plates (required by building regs, as some of the soleplates were directly onto earth), timber repairs, render and limewash. Majority of the cost was timber frame repairs. We had a great joiner and lime plasterer (married to each other which helped with the co-ordination) who worked directly for us. Our CO was very helpful.
Note that we had no idea of the extent of the timber frame repair until we had removed the cement render, but we are quite sure that if we had not removed the cement render the frame would have continued to deteriorate, which could have given us serous problems in the future, so we are sure that it was the right thing to do.
Been done about 18months now. Some settlement where the new dwarf walls were inserted, so some lime render repairs this year. Otherwise very pleased with the result, we are now both warm and dry. Hope this helps.

 

[Hatster]

Thanks Essex! That's very helpful - good to hear about a similar sort of experience.

I've emailed the Conservation Department to fix a meeting (probably in a month or so's time), so we'll go from there.

Are you in Essex, as your name suggests? We're near Cambridge so we'd be on the look-out for any recommendations for both surveyors who could give advice and/or trades-people if we decide to go this route.

(Thanks for the surveyor recommendation Nemesis!)

 

[Essex]

Forgot to say the house is a 15C timber frame.
We are near Sudbury in Suffolk, but just in Essex. We used the list kept by Essex County Council for our tradespeople, plus personal recommendations. I imagine Cambridge has a similar list for conservation work.

 

[BMcD]

If it's any help, I've just lime rendered about 200sq.m in The Midlands with 3 coat work plus a lot of dubbing out for around £15,000.00 give or take, including materials. The building was brick built with the previous cement p/dash already removed.
Quite what you'll find on removing your p/dash is anybodys guess so lets hope it's not too bad. All the best

 

[Gervase]

£15,000! :shock:
That's £75 a square metre - nice work if you can get it. No wonder I'm permanently busy and permanently skint; I must change my rates...

 

[Moo]

the appropriate materials will be suggested and approved by the CO

- or not, which is why it's always a good idea to get a second opinion on the forum.

When one of our ceilings collapsed the conservation officer insisted that we replace the laths. With money fast running out, and knowing no better at the time, we were eventually able to get permission to use metal, rather than wooden, lath.
At no stage was lime mentioned.
So the plasterer came and slapped up the gypsum.

 

[Nemesis]

The appropriate materials will in all probability be suggested and will have to be OK'd by the CO.

Lime or not in the case of internal ceiling plaster possibly makes little difference.

However, external render on a timber frame is rather more specialist, and we are now, I think, in recent times all more aware of the damage done by inappropriate renders. Additionally, as this is II* EH will have to have its say.

 

[Moo]

So I wonder what was the point of the metal lath?
As he worked, the plasterer grumbled about the amount of plaster he was having to use. At the end he asked what sort of finish I wanted. Apparently I could have ancient-wobbly-over-laths, spanish hacienda, or dead-smooth-over-plasterboard look. I chose the latter. It looks dead smart!

 

[BMcD]

Gervase Wrote:

That's £75 a square metre -

When you into account £5000 for materials and scaffold it comes to around £16.00 per sq.m. per coat and that's not including the dubbing out.