Period properties- damp,dpc,ventilation,drainage etc

paddylonglegs

Folks,thought I would share this great article on general issues found in period homes and some recommendation on how to fix. Have some issues with efflorescence at the moment so that's how I found it. It has also brought other issues to my attention that I had been wondering about. Hope it helps you, as there are always questions to be asked when fixing up an older house!

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

TheLastMohican

"Concentrations of hygroscopic salts, which are often found in masonry, can also absorb moisture from the air, especially at relative humilities above 75 per cent. In a room that is sometimes unoccupied, with fluctuating relative humidity levels, this can result in the regular appearance of salt blooms on the surface (‘cyclical efflorescence and deliquescence’), resulting in damage to vulnerable materials, and giving the appearance

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If this guy cannot proof read a few thousand words, can he really understand the forces of nature? Or read a damp meter?

paddylonglegs

TheLastMohican wrote: »

"Concentrations of hygroscopic salts, which are often found in masonry, can also absorb moisture from the air, especially at relative humilities above 75 per cent. In a room that is sometimes unoccupied, with fluctuating relative humidity levels, this can result in the regular appearance of salt blooms on the surface (‘cyclical efflorescence and deliquescence’), resulting in damage to vulnerable materials, and giving the appearance

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"

If this guy cannot proof read a few thousand words, can he really understand the forces of nature? Or read a damp meter?

Dunno. He's obviously some kind of a$$hole

NobodyImportant

Ah sure, might as well share, here are some i found handy:

http://www.periodliving.co.uk/renovating/expert-advice/marianne-suhr/damp-busting-mission

Why your non DPC home shouldnt have a concrete floor: http://www.telegraph.co.uk/property/propertyadvice/jeffhowell/7949821/Home-improvements-concrete-decision.html


PS - he may not have proof read it, but by God he knows more than 99% of builders in Ireland. I'm shocked by how little builders know about dealing with pre-concrete era housing. They work totally differently and you can distrub their 'ecosystem' and make damp problems worse or create problems where there was none before (like concrete floor instead of suspended timber floor).

paddylonglegs

NobodyImportant wrote: »

Ah sure, might as well share, here are some i found handy:

http://www.periodliving.co.uk/renovating/expert-advice/marianne-suhr/damp-busting-mission

Why your non DPC home shouldnt have a concrete floor: http://www.telegraph.co.uk/property/propertyadvice/jeffhowell/7949821/Home-improvements-concrete-decision.html


PS - he may not have proof read it, but by God he knows more than 99% of builders in Ireland. I'm shocked by how little builders know about dealing with pre-concrete era housing. They work totally differently and you can distrub their 'ecosystem' and make damp problems worse or create problems where there was none before (like concrete floor instead of suspended timber floor).

Yes, it seems that concrete is the best way to disturb these living, breathing animals that are period houses. I now have to think long and hard about getting the concrete render that was put on my house in the 50s removed.

Thanks for the links, will stick them on the reading list for bedtime reading. Apparently there is an Irish based book about renovating Irish properties out recently. Anyone come across it?

Dwork

I've an old house, was derelict when I bought it. Think large, and old. All floorboards were laid direct onto the earth, no dpms, stone walls 3' thick and damp, leaking roofs etc etc.
I started by digging a trench around the property, lowering the outer ground level to well below floor level and installing land drains and gutters with drains. I then repaired the roofs and flashings, eliminating rain ingress, so dry head and feet for the walls. I lifted all the floors, dug out the soil, dropping the level by 18", built stub walls and installed suspended joists and new timber floors. Next came plastering(which wrecked the plastering crews heads a I made them throw away their straight edges and finish trowels. I wanted old style, and I used bonding instead of skim as it has much greater permeability and gives a grainy finish.

For the "posh" rooms, I brought in a couple of my best carpenters and laid on timber pannelling, which took literally weeks per room. They also built coving to match the old, out of layer after layer of off the shelf timber mouldings to build up a heavy, deep profile. Anywhere the original granite flooring had survived, I cleaned it and left it untouched and unlifted, still on the earth underneath. I also insulated the bejasus out of the ceilings and roof, using high-spec foil where I didn't want a change in depth. Result, no damp, not a bit, -warm, dry and comfortable. I replaced all the rear (weather side windows with modern, and the fronts we made as copies of the rotten originals out of teak billets.

It's not finished, there's still stuff to do, but if you love old houses, there's a certain pleasure to be gained from saving a beautiful old building from dereliction. And no, you don't need to inject a dpc, or lay concrete floors, or hire an architect. If you do what feels right, more often than not, it is right. Oh yeah, and I'm a builder, so that sort of helps.:)

sarkozy

So I now own a 1905 house in Dublin 8. Standard construction for the time, no granite 'DPC', floor boards on earth. No problem mould/damp as such, the house breathes, but it's definitely a bit humid. It needs renovation, and with skyrocketing energy prices, I want it upgraded, insulated, etc. Also, it's small, so space is at a premium.

I'll be interested in learning about people's experiences here. We'll be recruiting an architect, but want to make sure we go for the right kinds of solutions.

paddylonglegs

Dwork. Have you had any thoughts on dry lining your walls? I have looked into thus and have had fairly good feedback from both builders and a conservation architect on how to go about it. Some people advise against internal insulation but the more I talk to, the more it seems to be able to work. Would love to dry line as I really need to try and keep warmth in. External insulation is too expensive

TheLastMohican

Dwork wrote: »

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Next came plastering(which wrecked the plastering crews heads a I made them throw away their straight edges and finish trowels. I wanted old style, and I used bonding instead of skim as it has much greater permeability and gives a grainy finish.
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Bonding on old outer stone walls? Seriously?

Dwork

paddylonglegs wrote: »

Dwork. Have you had any thoughts on dry lining your walls? I have looked into thus and have had fairly good feedback from both builders and a conservation architect on how to go about it. Some people advise against internal insulation but the more I talk to, the more it seems to be able to work. Would love to dry line as I really need to try and keep warmth in. External insulation is too expensive

I "dry-lined" the upstairs bedrooms, but did it very carefully, I left an air-space between the new lining and the old walls, it cost me an inch, but the rooms are very big. I battened the walls vertically, 400 centers, then I used a high grade foil insulation, lapped to allow moisture fall into the vented gap created, ie started at the top and worked down. The air space behind the foil is like a hurricane zone when the wind blows, so loads of drying:D I sealed over that with a membrane, tape and sealer(dear stuff btw:() and slabbed over that with green(moisture resist)plasterboard.

You need to watch the detail at opes like sockets etc to ensure your not breaching the air-tightness or your sockets will become mini blast chillers in cold, windy weather. We then "skimmed" that with bonding to match the old existing walls. It ended up indistinguishable from the 300 year old lime rendered stone in other areas of the house. I used kingspan and foil on the ceiling btw, kingspan between the joists and foil under it to prevent cold bridging. The difference in warmth and heating bills is night and day and for the first time all the upper rooms are a.totally dry and damp free(as are our clothes(some people will get this bit:)) and b.you could heat it with a candle. Well, well worth doing IMO just for quality of life if nothing else.

Whatever you do, IMO, you need to allow air circulate at the face of the walls. If you don't, you'll have condensation issues, big time. No matter what anyone says, you're going to get condensation on a dry-lined wall, somwhere, either inside the room, or between the lining and the wall. If that's a stagnant space, that condensation will sit. You need moving air to dry that moisture out. I've seen some awful disasters of "drylining" on older properties, where condensation was literally streaming down every wall on the inside, effectivly creating a sort of polytunnell effect. You need to proceed with some caution, and keep air movement in mind.

Dwork

TheLastMohican wrote: »

Bonding on old outer stone walls? Seriously?

Are ya mad?:) Inner walls. The outside is lime rendered. I do this for a living, have done so for 20 years. I'm not quite that daft, thanks.:D

TheLastMohican

Dwork wrote: »

Are ya mad?:) Inner walls. The outside is lime rendered. I do this for a living, have done so for 20 years. I'm not quite that daft, thanks.:D

As an apprentice plasterer, we were warned not to put Carlite Bonding on the inside of OUTER walls. Have a read of their MSD sheet.

Dwork

TheLastMohican wrote: »

As an apprentice plasterer, we were warned not to put Carlite Bonding on the inside of OUTER walls. Have a read of their MSD sheet.

As a builder with 3 full time plasterers, I've never put bonding on an exterior wall, either internal or external. These are internal dividing stud walls. I've had a fair few looks at their MSD sheets. We're talking decorative finish here, not weatherproofing. I get where you're coming from, but your barking up the wrong wall. Also, the houses I work on, you didn't do in your apprenticeship. Don't presume to teach your grandmother how to suck eggs.

NobodyImportant

@Dwork,

Where did the wind come from that was behind the dry lining? We have dry lined two internal walls, the dry lining is up against the wall and fastened to the wall with mushrooms. Its floor to ceiling. If we sat it out with battens, it would still be sealed and floor and ceiling and have no circulating air. The dry lining has foil within it, so should stop moisture from the room penetrating through and causing interstertial condensation? Its up about 6 months now and no problems. We also dont have a particularly warm house (living in between 13-15 degrees) and it isnt particularly humid either (55-62% humidity usually).

paddylonglegs

+1 on answers to the above question

MissSteel

DWork, How did you create the air movement behind the insulation, did you vent from outside or into the room itself? Also what type of heating system do you have? My OH and I are just about to start a major renovation of a period house and we are particularly worried out how to insulate and heat it!

AMG86

The Department of the Environment has published a guide re upgrading the thermal efficiency of ttraditional buildings built before the middle of the 20th century. They present a challenge but with careful planning and skilled workmanship they can be enhanced for contemporary living. The guide will help in making the right decisions on how to increase the comfort and reduce the energy use of a traditional building by advising on (i) understanding how a traditional building works (ii) how to maximise the level of comfort for its occupants and (iii) choosing the most cost effective energy options http://www.dublincity.ie/Planning/HeritageConservation/Conservation/Documents/Energy%20Efficiency%20in%20Traditional%20Buildings.pdf

paddylonglegs

MissSteel wrote: »

DWork, How did you create the air movement behind the insulation, did you vent from outside or into the room itself? Also what type of heating system do you have? My OH and I are just about to start a major renovation of a period house and we are particularly worried out how to insulate and heat it!

Talking to an experienced builder today re dry-lining period house. When creating a void between the wall and insulation board, instead of using wooden battens, use metal battens called Top Hats. They are u shaped and screw fixed to wall, minimising contact with the wall. Can anyone else vouge for this?

paddylonglegs

http://www.igs.ie/Events.aspx

Irish Georgian society has lectures until April on preserving period properties. Looks interesting

MissSteel

Hi Paddylonglegs! We were intending to use metal battens alright but still unsure as to how to place the vents. I suppose we will have to vent back into the room, as we wont be able to put vents on the external walls. Doing around the windows will be especially tricky.
I would like to go to the lectures, but from reading the guide that AMG86 posted it seems that they are very against insulating period properties, so it might not be of much use to me! I can understand why in a Period house with beautiful cornices and internal features but ours has nothing of the sort!

dathi

worse than pointless venting the dry lining back into the room as the warm moist air in your room will travel through the vent and hit the cold external wall and condense causing serious damp and rot behind the dry lining. also any benefit of the insulation will be negated by the vent allowing the hot air to come in contact with the cold wall

NobodyImportant

I'm also confused about an idea.

You dry line say one external wall, with board that has foil behind it. You tape the joints with foil tape. Why would it get all moist behind the board then if there is a barrier?

I'm hoping to board a few external walls with just 38mm insulated board, so the temperature difference wont be so great and hopefully we wont have such a high interstertial condensation risk. The house is rarely above 15 degrees in winter and humidity is kept at about 65% max.

MissSteel

Hi Dathi, Thanks for that, you make perfect sense! As you can propably tell i am completely out of my depth here! I wonder could we vent the dry lining from the ground floor through the suspended floor to the space underneath which is vented at the front of the House.
What about the first floor? Would you do the same with the dry lining here, and have it joining into the vented space for the room below?

whizbang

vent the dry lining from the ground floor through the suspended floor to the space underneath which is vented

+++1 perfect. But also look at some window manufacturers, can supply systems for venting internal cavities, and living space combined.

MissSteel

I put this idea to the OH and he has changed his mind again. He reckons that the air flow between the insulated board and the stone wall would cancel out the insulating properties of the board.. much like a cavity space in a modern build which later gets pumped! It will be very hard to create a perfect seal with the boards that will not allow heat loss through joints and such. I was looking at open cell spray foam last night online, has anyone any experience with this? Its claims to be breathable and no issues with sealing joints..etc
I would not like to spray directly on the wall, as it is ~350yr’s old, I don’t want to cause any irreversible damage to it.. could I put some sort of breathable membrane on the wall, battens, then spray with open cell foam and cover with breathable plasterboard?
I would probably install vents in the floor with this method to ensure sufficient ventilation in the room, I’m not sure at the moment if the windows we will be installing will have vents in them as they are traditional timber sash windows.

whizbang

interesting idea with the spray foam. I dont know enough to comment.

But maybe put the membrane between the insulation and air gap. - that will cancel the airflow effect, if that helps you to understand it.
Closed cell rigid foam boards as insulation wont care how much cold airflow is behind them. just pay attention to the jointing and sealing.
The Airflow needed for moisture ventilation is quite low; i dont have values to hand, but it wouldn't be in the 'draft' range