Stone Cottage Renovation - still confused!

mike72

Hi guys,

I own a detached one and a half storey cottage. The walls are of stone rubble contruction. The outer walls are finished with a wet dash and standard exterior paint. The ground floor is very thin concrete. No DPC. Gutted the house last week and what we have now is a roof, a first floor, and all the walls and chimney have been stripped back to the stone internally. Front north wall and 1 gable attached to council and private properties, so french drains and external insulation is just not possible. Can't afford to replace the wet dash with a lime render, so just going to have to do what I can inside. Ground floor is lower than the footpath outside. Walls downstairs have rising damp issue. Putting some french doors in the southern wall to let the sun in, if the walls can take it.
So bearing all that information in mind, what do I do next?

1. What's my best option for the floor? DPC and insulation?

2. The walls etc regarding insulation? I have swayed away from drylining due to the associated health risks etc, so what else? Woodfibre boards, hemcrete, biofoam between studs, dynamite?

I did see a site with hempcrete (or the like) lumped on to the stone directly leaving a rough finish which still showed some of the shape of the stones beneath and supposedly insulated the wall. Looked quite nice, but would it keep me warm? Also bear in mind that space is really at a premium. Apologies if a lot of this stuff has been covered in other discussions, but I can't seem to find any discussion that fits my situation closely enough to help me make a decision.

mike72

Ordered the steel for the proposed french doors (5ft wide) today. Here's hoping we don't level the house.

Anyone got any suggestions on how to proceed in terms of insulation, floors, damp? Hoping I can tap into the vast array of minds on this forum. Just a small piece of your extensive knowledge would be a tremendous help to me. Please don't leave a newly married couple stranded in a cold damp house this Christmas.

YOU have the power to help!

Anyone? Anyone?

No6

By the sound of things mike you badly need to employ a professional (Architect, Engineer, Arch Tech) to look at your house and tell you what you should do, you have to many questions for me here. Find someone who has experience of refurbishment. One month is a very very short timescale for such a job! Good Luck

mike72

Thanks for the reply no6.
Being realistic we won't be done in a month of course. We will short term rent in the meantime.
Architect is a dry line fan, so no joy there. Thought I'd see what the forward thinkers in here could offer in the way of advice.
Any further thoughts?

Walls?
Floors?
Roof?

Poor Uncle Tom

mike72 wrote: »

Architect is a dry line fan,

This may be the case, but it's options you need not personal preferences. There must be more than one professional around for you to get advice from.? As No6 said there's a lot going on here, insulations, dpc's, floor and ground levels, walls at boundaries, etc. You need on-site professional advice, get some.

mike72

Thanks for the reply Uncle Bob.
I know there is a lot to be considered.

Just looking for ideas to discuss with the professionals. The walls are my primary concern. This will only be a starter home and eventually just a games room/office/guest accomodation when we build a new home. Perhaps I'll just go with the current suggestions and plaster the walls and glue insulated plaster board to them? Cheap and cheerfull, if not that healthy.

Poor Uncle Tom

mike72 wrote: »

Perhaps I'll just go with the current suggestions and plaster the walls and glue insulated plaster board to them? Cheap and cheerfull, if not that healthy.

okay, maybe you could consider the more traditional drylining method using studwork on dpc's with vapour checks, insulation and plaster slabs, incorporating a ventilation system. I think you'll find this to be the healthier option.

mike72

Cheers Uncle Tom.

Should I plaster the internal wall first or is this necessary?

I've seen a lot of debate on where to put the various barriers and vents etc. What order would you suggest?

Would I use the DPC under the floor and continue on up the walls?

No6

Mike its a DPM under the floor (Damp Proof Membrane) this is a 2000 guage polythene sheet, it is not vapor perimiable and acts as a complete barrier to moisture. You mention an area with excessive damp as it is partially underground. You could consider turning the DPM up the walls here to form a barrier, its cheap but dosn't remove the problem.

you'll need a DPC (Damp Proof Course) which in your walls will either be injected silicon or an electro osmotic system.

Put lots of insulation in your floor, at least 75mm but 100 or more if you can afford it and have the room.

I would dryline with the walls with thermal board but as you have an issue with this try studding and hemp (expensive!!) or similar fibreous insulation with vapor barriers and breather membranes,

Are you removing the slates from the roof if so then a standard roof construction, slates battens felt and 600mm fibreglass insulation on ceiling (if possible) is fne, for sloped roofs you'll have to insulated between the rafters and underneath them with a kingspan type roof board and a thermal board.

I hope this helps a little!!!

mike72

No6, Apologies for the incorrect use of the termonology. As you can tell I'm an idiot at this sort of thing. My brother (and labourer/foreman)is better, but he doesn't have broadband, so I print out the replies and bring them to him.

The DPC: I've read that injected silicon doesn't work so well in stone rubble walls. Is this not true? I'm not contradicting you, don't get me wrong. Just posting some things that I've read on various forums. There are also skeptics about the electro osmotic system, but I'm interested if you think these things will help.

Insulation in the floor: It's a very thin concrete slab which we'll dig up easily. I guess we can make as much room as we need then, in addition to raising the floor slightly to help with the levels. What type of product would you suggest we use here?

Drylining: I don't actually have any issue with this. Again I've just read that it leads to mould growth. Perhaps I've misunderstood. I'm open to all suggestions. Would thermal boards directly onto the stone with plastic dowels/plugs (don't know what they're called) provide some sort of air cavity, considering the very rough uneven nature of the walls.

Roof: We were just discussing this today. We removed all the plaster boards from the rafters and the roof isn't in great shape. The timbers seem ok, but we could see daylight in 1 or 2 spots. The slates all seem to have had gaps filled with plaster or the like.

I guess it's too big of a job overall to do correctly, so perhaps I should just go the simplest route to tide us over 'till we build a new house. It would then be mostly used as an office/workshop. Would I be as well off spraying that much maligned foam onto the slates and between rafters and thermal board over that? If it rotted the timbers in a few years then I would only end up doing what needs to be done anyway and re roofing the house.

Your reply has helped, and thanks.

PureBred

I'm doing something similar to Mike72.

The walls in the house are mass conrete as its called. Dont know how to go about prventing dampness in the walls. How would u use injected siliconin a concrete wall. ie no cavity.

Also the floors in the house were originally raised timber floors with what appeared to be vents to the outside. I have removed this and layed concrete base over the rough concrete foundation that was there. Thinking about putting down DPM,insulation and screeding over this. Would prob run DPM up walls aswell. Would this suffice??

How are you getting along with yours Mike72???

mike72

Hi Ricfeen,

Despite common sense and advice stating I'm in a no win situation, the work continues. Have now got a finished opening for french doors and a new window opening in the south wall, so the house is much brighter than before. The chimney is coming out this week and the existing first floor will be supported with two large RSJ's with the timbers slotting into the channel in the RSJ's to leave a perfectly flat finish. That will leave a single large room downstairs and provide room for a small bathroom upstairs. In two weeks the slates will be coming off and we will replace incorporating solitex or the like underneath. Will probably do the fascia, soffit, gutters also. We will also build a mock chimney stack at this stage.
The dampness issue still remains, so will probably try a whole host of different ideas to tackle it. I've heard of a suggestion where you dig a channel around the inside perimeter of the walls and lay some perforated pipe draining to the outside. I've no idea if this will work, but it's cheap to try, so worth a pop. I will stray away from dry lining for the moment though. Figure I'll just heavily insulate the roof and ceeling and see how cold it is in the winter. This will give me a chance to monitor the drying of the internal walls. Had a builder look at the house. He suggested replacing the wet dash outside with same (or nap plaster finish), but with a water proofing agent in the mix. Seems to go against the idea of allowing these old walls to breathe, but maybe more practical in the current situation? Still considering that one. If all else fails though, it will be (like you considered) lapping the damp proof up the walls and drylining with vents to the outside.

PureBred

Ya i took out a chimney in my house also. There were 5 fireplaces in mine. Took out one back to back chimney and you'd be amazed about the amount of sapce i have gained. Was going to go for a mock chimney but decided it wasn't needed. Still have 1 anyways.

I saw some damp proof paint like stuff in the local co-op. Says that you can paint it on external/internal walls and floors to keep out moisture. Think the brand is Aquaseal. Anyone ever use this???

Since i put a new roof on the house i have't really seen anymore moisture penetrating but just don't want to run into the disastrous situation of ripping up timer floors/screed in a few months time to fix rising damp if thats what it is.

mike72

Chimney is now gone and has opened up the the house nicely. We now have one room downstairs and one up. Will keep the downstairs open plan and divide upstairs in to 1 large bedroom, 1 small, and a small bathroom. Also toying with the idea of building a small back kitchen, but this of course will blow the budget big time. I'm thinking that I may never get to build the new house behind with the serious possibility of redundancy looming large in the next 10 weeks, so it's probably the right thing to do.

Are you going the DIY route Ricfeen, or have you had tradesmen in? We have been totally diy so far. Although we have a professional roofer doing the slates, purely because hiring out scaffolding is quite expensive, so it's not much more to pay a guy to do the job.

What part of the country are you in?

Have you decided on how you are going to tackle the walls yet?

Any other readers of this post, please feel free to offer your two cents.

PureBred

Well mike i have got in a blocklayer and a chippie so far. Just doing it by pay as you go for the time being. Have built a bay window of the sied of the house and a new porch also. Just waiting on my windows to arrive now.

Going to slab the walls with the stuff that you stick on. Seen it on telly.

Going to get the Aquaseal stuff just to paint underneath the DPM that i put down to be sure. Will run this up the walls a bit too. Then some insulation and that poured concrete screed stuff i saw on telly.
Cant think of the name of it now.

Tester46

Be aware there seem to be 2 main approaches to renovating old houses like yours. The first is to use modern methods and materials to seal (thermally, damp, etc) the entire inside of the house, or else to seal it on the outside e.g. a new cement render.

The other approach is to recognise that these are old stone houses which were designed to breathe. Apart from any arty-farty-newworld-hippy stuff, there are supposed to be health benefits with this approach and of course it is being sympathetic to the way the houses were built in the first place.

I am in the middle of a job like yours. I have gone for a new lime render on the outside (more expensive than cement render, but beautiful), hemp insulation on the inside (not half as expensive as some people seem to think) with a breathable membrane over it. Hemp insulation is a bit thicker than the new plastic/foam stuff but well worth it in my personal opinion. I have smelled both the hemp insulation and a new foil-backed foam one. One of them smells like a toxic waste dump, the other smells like newly cut hay. I know which I want surrounding me and my family in my house.

I have not gone for any injected chemicals or electro-osmotic system in the walls as (a) I don't believe they are necessary (in my case at least) as a breatheable stone walled house should be just fine once it is lived in and heated. That said, just make sure that whoever is advising you knows what he is talking about and does not have any particular product to sell. If you're happy with them,follow their advice and use facilities like boards.ie to get lots of good info.

DinnyBatman

Does the hemp insulation look like plasterboard? I will be shortly needing to insulate an old farmhouse, but want to keep the old stonework inside the house cause its gorgeous! I don't want it covered up, but still want keep mrs batman toasty in winter. Whats the best thing to use?

No6

DinnyBatman wrote: »

Does the hemp insulation look like plasterboard? I will be shortly needing to insulate an old farmhouse, but want to keep the old stonework inside the house cause its gorgeous! I don't want it covered up, but still want keep mrs batman toasty in winter. Whats the best thing to use?

I'm afraid Batman you only have two options, to leave the internal stonework exposed

a) No insulation at all, get a woolly jumper for Mrs Batman or

b) External insulation all around which at approx 100 per m² is the most expensive option you can pick and to be honest I'm not sure how old stone walls would behave with external insulation.

mike72

Tester46

How much more expensive (in terms of %) is the lime render? I am strongly leaning towards this approach. Is it the materials that cost the extra, or does the labour cost more also?

Also, really considering some sort of breathable dry lining like hemp. What type of products did you use here? (studs, hemp quilts, breather membrane, fermacell boards?)

Tester46

mike72 wrote: »

Tester46

How much more expensive (in terms of %) is the lime render? I am strongly leaning towards this approach. Is it the materials that cost the extra, or does the labour cost more also?

Also, really considering some sort of breathable dry lining like hemp. What type of products did you use here? (studs, hemp quilts, breather membrane, fermacell boards?)

There are not many people who specialise in lime render and so you need to shop around. The quotes I got from different people varied wildly - one was double the one I went for in the end). I contacted the Traditional Lime Co in Carlow to get names of lime plasterers. The guy nearest to you may not be the one you end up going for. In terms of % difference I don't know as I was never going for anything else. The materials and the labour are more expensive, but (in my opinion) there is no choice. Plus, the lime itself is a beautiful finish so there's no need to paint it or have a finishing render, so that's a saving over cement.

The hemp insulation was Thermo Hemp (see here) which comes in from Germany. It is a mat 100mm thick and went between wood battens directly against the stone wall. I found the company that sold it to be very helpful. We used their Intello Plus as a vapour barrier, and it was taped with a breathable tape. To save money, we ended up using regular gypsum plasterboard - we were told (by the guy who would have sold us the more expensive breathable board) that while it is not as breathable as other boards, so long as it was not the foil-backed type it would do the job just fine.

So, from the outside in we had:
- lime render (3-4 coats)
- stone wall
- hemp mats between battens
- vapour barrier
- plaster board
- breathable paint

It's just in so we'll see how good it is. We reckon it'll be fine though.

Tester46

The other advantage of the hemp insulation is that it arrives in big bales with big hemp leaves printed on the sides. The builders were delighted and it'll give your local garda drugs unit something to do for the morning as you explain that no, you are not a master criminal smuggling millions of euros of grass in big bales with a big green hemp leaf on the side!

Make sure you explain to the builders that it is not mind altering, or else you'll find handfuls of the stuff disappearing in sandwich bags all day long.

mike72

Tester46 wrote: »

There are not many people who specialise in lime render and so you need to shop around. The quotes I got from different people varied wildly - one was double the one I went for in the end). I contacted the Traditional Lime Co in Carlow to get names of lime plasterers. The guy nearest to you may not be the one you end up going for. In terms of % difference I don't know as I was never going for anything else. The materials and the labour are more expensive, but (in my opinion) there is no choice. Plus, the lime itself is a beautiful finish so there's no need to paint it or have a finishing render, so that's a saving over cement.

The hemp insulation was Thermo Hemp (see here) which comes in from Germany. It is a mat 100mm thick and went between wood battens directly against the stone wall. I found the company that sold it to be very helpful. We used their Intello Plus as a vapour barrier, and it was taped with a breathable tape. To save money, we ended up using regular gypsum plasterboard - we were told (by the guy who would have sold us the more expensive breathable board) that while it is not as breathable as other boards, so long as it was not the foil-backed type it would do the job just fine.

So, from the outside in we had:
- lime render (3-4 coats)
- stone wall
- hemp mats between battens
- vapour barrier
- plaster board
- breathable paint

It's just in so we'll see how good it is. We reckon it'll be fine though.

Thinking I'll get some prices on this method. Sounds good.

Would you be able to estimate a rough sq meter price for the external lime plaster inc labour?

I'm assuming you just used a standard skim coat on the plasterboard inside, or is a special plaster required?

What way did you insulate your roof, hemp again? Is there need for breathability here, or will the standard approach (ie fibreglass, or insulation board) be fine?

Tester46

mike72 wrote: »

Thinking I'll get some prices on this method. Sounds good.

Would you be able to estimate a rough sq meter price for the external lime plaster inc labour?

I'm assuming you just used a standard skim coat on the plasterboard inside, or is a special plaster required?

What way did you insulate your roof, hemp again? Is there need for breathability here, or will the standard approach (ie fibreglass, or insulation board) be fine?

I don't know the sqm cost - just the overall price, sorry. In the attic we used recycled glass wool (lots of it as we aren't using the attic for storage) and a small bit of kingspan down near the wall plate to avoid blocking the attic ventilation.

mike72

Tester46 wrote: »

So, from the outside in we had:
- lime render (3-4 coats)
- stone wall
- hemp mats between battens
- vapour barrier
- plaster board
- breathable paint

It's just in so we'll see how good it is. We reckon it'll be fine though.

After stripping the horrible cement dash of the outside walls we decided we might like to keep the natural stone look rather than plaster over it again. The fact that is was a nightmare removing the dash in the first place was a factor in this also. We now have to consider how pointing the stone with lime mortar will affect our internal set up.

We have planned on using the same set up as you:
stone wall, hemp mats, intello, plasterboard, breathable paint.
I'm wondering will lime pointing provide sufficient protectection from the elements for this set up to work, or should we put intello on the inside of the hemp also just in case?

Thoughts anyone??

Tester46

mike72 wrote: »

After stripping the horrible cement dash of the outside walls we decided we might like to keep the natural stone look rather than plaster over it again. The fact that is was a nightmare removing the dash in the first place was a factor in this also. We now have to consider how pointing the stone with lime mortar will affect our internal set up.

Just bear in mind that the house was designed and built with a render on the outside. If you remove the render and don't replace it, you have lost an integral part of the building's weatherproofness. My personal (and uneducated opinion) is that exposing the stone looks good, but is not good for the building. Plus, by the time you have repointed all the stones, it doesn't look so old and natural any more. Repointing is only an option if the stones are very large and sound. Lots of small stones or cracked stones will be asking for trouble.

If it was me, I'd go for the lime render. It could well be cheaper as it is less fiddly to apply. Plus it is the finish that is meant to be on the building. PM me if you want the name of our lime renderer.

yekim

I'm doing a similar job on my old cottage and I'm planning to raise the overall height of the cottage to:
1. Raise the stone wall up to match an existing extension
2. To give me space for two bedrooms.

my question is, can a concrete tie - beam be laid on top of stone and does it have to be a particular type for breathability. I would like to raise height by 2-3 feet. Is this advisable, and how does this affect dampness control and insulation. Would a lime-based concrete be best

brendankelly

Tester 46 your knowledge of lime plastering is very good. I know of a job where the home owner is wrapping the outside of his building with a hemp/lime insulation and plastering it with a lime plaster. What are your views on this method.

heinbloed

Quote from tester 46:

So, from the outside in we had:
- lime render (3-4 coats)
- stone wall
- hemp mats between battens
- vapour barrier
- plaster board
- breathable paint

I suppose a dynamic moisture calculation wasn't done ........this smells of mould and physical destruction of load bearing elements, for example timber lintels and floor beams.

It's just in so we'll see how good it is.

Since this post is over a year old we could inspect the hidden risk areas. Was this done?
Was this build-up a DIY aproach, who is responsible in case of failure ?

Poor Uncle Tom

heinbloed wrote: »

Quote from tester 46:



I suppose a dynamic moisture calculation wasn't done ........this smells of mould and physical destruction of load bearing elements, for example timber lintels and floor beams.





Since this post is over a year old we could inspect the hidden risk areas. Was this done?
Was this build-up a DIY aproach, who is responsible in case of failure ?

Nit picking posts from a thread this old can be seen as Trolling, imo.

To quote a phrase "you've missed the bus, have a bit of dignity and stop shouting after it".

It's best to leave old threads rest in peace, if anyone has a question for a particular poster, then it is best PM'ed to them. This is even more apt in this case as the poster in question has not posted in the C&P forum since 12th November 2009.

LesPaul01

Tester46 wrote: »

mike72 wrote: »

Tester46

How much more expensive (in terms of %) is the lime render? I am strongly leaning towards this approach. Is it the materials that cost the extra, or does the labour cost more also?

Also, really considering some sort of breathable dry lining like hemp. What type of products did you use here? (studs, hemp quilts, breather membrane, fermacell boards?)

There are not many people who specialise in lime render and so you need to shop around. The quotes I got from different people varied wildly - one was double the one I went for in the end). I contacted the Traditional Lime Co in Carlow to get names of lime plasterers. The guy nearest to you may not be the one you end up going for. In terms of % difference I don't know as I was never going for anything else. The materials and the labour are more expensive, but (in my opinion) there is no choice. Plus, the lime itself is a beautiful finish so there's no need to paint it or have a finishing render, so that's a saving over cement.

The hemp insulation was Thermo Hemp (see here) which comes in from Germany. It is a mat 100mm thick and went between wood battens directly against the stone wall. I found the company that sold it to be very helpful. We used their Intello Plus as a vapour barrier, and it was taped with a breathable tape. To save money, we ended up using regular gypsum plasterboard - we were told (by the guy who would have sold us the more expensive breathable board) that while it is not as breathable as other boards, so long as it was not the foil-backed type it would do the job just fine.

So, from the outside in we had:
- lime render (3-4 coats)
- stone wall
- hemp mats between battens
- vapour barrier
- plaster board
- breathable paint

It's just in so we'll see how good it is. We reckon it'll be fine though.

So how has everything performed. Anything you'd like to have done differently?

muffler

LesPaul01 wrote: »

So how has everything performed. Anything you'd like to have done differently?

Have you read the moderator's instruction just above your post?

Thought not.

Thread closed.