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cavity wall insulation next mis-selling scandal?


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15 minutes ago, StarsEnd said:

Thanks CrashMonitor, that's some really useful info there. Are loft ventilation systems expensive to put in?

One thing I was looking at was a piece of equipment that doesn't look dissimilar to a bathroom extractor fan but is on permanently and has a built in heat exchanger; the idea being that it is constantly changing the air in the house but without losing all your heat. Not sure as o how effective this would be. It's a small semi so possibly it would make some difference. 

I think mine was about 600 quid fitted. Previous house so I have no details now of the unit type.

Edited by crashmonitor
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47 minutes ago, 2buyornot2buy said:

Have you tried opening a window and ventilating the place? Are the fires boarded up? Old houses are supposed to be drafty. 

I suspect that you'd need to have to the windows open quite a lot to make a substantial difference, not really that practical in the winter. It does have one small fireplace which is indeed boarded up.

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17 hours ago, The Knimbies who say No said:

This stuff is worth a look, assuming you have access to the roof. Got to Costco for the best price, under £25 and occasionally cheaper on offer.

 

http://www.wetandforget.co.uk

They do bags of moss killer stuff at the allotment store .. about 80p a lb I think. Ammonium sulphate .. Lovely stuff. Sprinkle it on and the moss disappears.

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25 minutes ago, StarsEnd said:

I suspect that you'd need to have to the windows open quite a lot to make a substantial difference, not really that practical in the winter. It does have one small fireplace which is indeed boarded up.

Sometimes makes thing worse exchanging damp air from inside with even damper air from outside.

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3 hours ago, StarsEnd said:

Interesting thread.

Does anybody know what would cause extreme condensation? To the point where most of the windows in a house are literally sopping wet? There is also black mildew forming on some walls.

The house is a 1930s semi.

Is it just the way they were built back them? Short of having to have a dehumidifier on for a couple of hours every day are there any other solutions? Any help much appreciated.

I live in Devon having moved from the SE and never experience such damp in all houses I have lived in down here. The sort of damp where you put your smart leather shoes away and when you get them out next time they are covered in mould. 

I fit positive pressure ventilation almost as soon as I move in now. It is really just a fan that draws in cold air from the loft and blows it into the house and forces the damp air out of the trickle vents etc. The theory is that the cold air expands when it enters the house so even if relatively damp when it comes in as it expand it's % humidity drops. It works best the colder it is like now. Autumn when the temperature differential is small and the humidity is high it is less effective but still better than without. We used to use the Kacher window vac each morning, now we don't use it at all (there is still a small amount on the Windows with weather like this but clears on its own.

I have not seen a definitive study but there is a case for it not adding to your heating bill as despite brining in cold air that needs heating the dryer air requires less energy to heat and comfort is felt at lower thermostat temperature.

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Moved into this house 3+ years ago and had condensation issues on windows and mold forming on windows frames, recesses, room corners and wallpaper. Got really bad when the outside air temp fell below 5degreesC when all windows would be covered with water in the mornings.

Tried a lot of the usual things:
- Tumble dryer with external vent.
- Always use the kichten extractor when coocking.
- Leave bathroom window open to vent during and after a shower.
- De-humidifyer on landing, collecting 4 liters of water from the air on bad days.

Eventually discovered a leaking mains joint under the sink cabinets, when the last occupier probably disturbed removing their washing machine (yanking pipes from above). By the time I discovered the leak (3 years later), water and salts where visible on the outside wall as 3+ liters per hour was flowing into the concrete base of the house! Unmetered water supply so didn't cost or show up on the bill. Once I put a stop to the under floor pond in the kitchen the relative humidity numbers dropped from 70+ to around 45 in less than a week.

Anyway, 2 years into this leak I had cavity wall insulation (small grey polly balls injected into many drilled holes) between brick and thermalite breeze block, plus extra thick loft insulation, all for free on the end of a gov't deal. There was no noticable increase in condensation or damp. After the leak was fixed the house was easier to heat, mostly due to the extra insulation, I can run the central heating 3+ degreesC warmer (both measured and at the stat) for the same energy usage before the added extra loft and wall insulation. I used to struggle to maintain 19 degreesC, now 22 degreesC day and night during the winter. I've collected a spreadsheet over 3 years of gas/elect meter readings for more accurate energy usage comparisons.  

Edited by DarkHorseWaits-NoMore
typo's
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19 hours ago, Untoward said:

Believe me, it is down to the Architect's detail and the Contractor's due diligence.

There is nothing wrong with that product, if the design detail is correct and the installation is sound. The corner-cutting contractor tends to be the problem.

Rockwool is a bad idea full stop `its like a sponge on new build its generally attached to thermalite blocks (also like a sponge) then the stud wall is on the other side of the block 

The common failure points are  around window /door apertures basically the seal fails i`m guessing due to thermal expansion contraction 

Just look at the temperature restrictions concerning the application when it comes to acrylic and silicone render systems ,how often are they adhered to ,then add in the 25 year max guarantee it`s a poor system when used with rock wool boards hence the move to PU or polystyrene boards  

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59 minutes ago, long time lurking said:

Rockwool is a bad idea full stop `its like a sponge on new build its generally attached to thermalite blocks (also like a sponge) then the stud wall is on the other side of the block 

The common failure points are  around window /door apertures basically the seal fails i`m guessing due to thermal expansion contraction 

Just look at the temperature restrictions concerning the application when it comes to acrylic and silicone render systems ,how often are they adhered to ,then add in the 25 year max guarantee it`s a poor system when used with rock wool boards hence the move to PU or polystyrene boards  

The trade name is like hoover to vacuum cleaners. Rockwool is your bog standard, retro loose lay, roof insulation for lofts. I assumed they did a rigid PIR board...but a quick check on their website reveals they don't.  So apologies for getting that wrong. In theory, if the product is foil-faced and taped correctly, it should be ok. But that is never going to happen across a whole building, the risk is too great. I would never specify it.

A rigid PIR board by Celotex or Kingspan (or similar approved) is more suited to the task and far higher 'U' values can be achieved on a far thinner board. Also saves a fortune in reducing cavity wall thickness' and associated foundations / work around openings.

Render systems are a disaster full stop. Nothing wrong with traditional render but I have seen insulated render systems fail after 5 years. The 25 year warranty is not worth the paper it is written on. Manufacturer and Building Contractor blame each other and then they blame the sub-contractor when they discover "Bodge it Brothers" no longer trade under the same name. They would far rather drag it through the courts than pay a claim.

For the benefit of everybody on this thread, this document should come in very handy. It is the detailing bible. There are far slicker and more beautiful details but these are the bread and butter details, especially for residential: http://www.robustdetails.com/

And for Architectural enthusiasts who appreciate the true beauty in the detail of a building: http://www.detail-online.com/

 

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21 hours ago, Untoward said:

Exactly. Basic construction knowledge.  

 

Indeed, I'd have thought it was better making sure drafts were removed and that convection wasn't removing heat inside the cavity.

The Thermal Conductivity of air is 0.024 W/mK, where as the fillers the use are typically 0.036 W/mK

So air isn't a bad insulator - just need to make sure it doesn't move heat about by convection.

 

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27 minutes ago, Untoward said:

The trade name is like hoover to vacuum cleaners. Rockwool is your bog standard, retro loose lay, roof insulation for lofts. I assumed they did a rigid PIR board...but a quick check on their website reveals they don't.  So apologies for getting that wrong. In theory, if the product is foil-faced and taped correctly, it should be ok. But that is never going to happen across a whole building, the risk is too great. I would never specify it.

A rigid PIR board by Celotex or Kingspan (or similar approved) is more suited to the task and far higher 'U' values can be achieved on a far thinner board. Also saves a fortune in reducing cavity wall thickness' and associated foundations / work around openings.

Render systems are a disaster full stop. Nothing wrong with traditional render but I have seen insulated render systems fail after 5 years. The 25 year warranty is not worth the paper it is written on. Manufacturer and Building Contractor blame each other and then they blame the sub-contractor when they discover "Bodge it Brothers" no longer trade under the same name. They would far rather drag it through the courts than pay a claim.

For the benefit of everybody on this thread, this document should come in very handy. It is the detailing bible. There are far slicker and more beautiful details but these are the bread and butter details, especially for residential: http://www.robustdetails.com/

And for Architectural enthusiasts who appreciate the true beauty in the detail of a building: http://www.detail-online.com/

 

  No what was used at the beginning was not foil faced it was a compressed  "board" / slab much like this http://www.insulationgiant.co.uk/Rockwool-RWA45-75mm-Acoustic-Insulation-Slab-1200mm-x-600mm/p/961937?gclid=CJqYxsOP2dECFQ4R0wodi2oOXg but they had a T&G arrangement on the sides 

The base coat was rendered on to the open fibers  then a carbon fiber /Kevlar mesh in-bedded into it whilst the the base coat was still wet then the top coat applied once the base had cured  that was  usually textured and coloured

Some places used a membrane in between the slab and the block some never ...i`m talking mainly hospitals and high rise flats built 10-12 years ago

The whole system when used in high rises is about two things R value and weight saving ...i was lead to believe the latter  is where the real savings are it requires  a far less robust structure to support  it 

 

Edit:: to add this system was not a "cavity" system it is, render to slab ,slab to thermalite block (via a wall tie type system similar to those used with kingspan boards in a cavity wall ) stud wall to block on the inside

Edited by long time lurking
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30 minutes ago, Untoward said:

.

Render systems are a disaster full stop. Nothing wrong with traditional render but I have seen insulated render systems fail after 5 years. The 25 year warranty is not worth the paper it is written on. Manufacturer and Building Contractor blame each other and then they blame the sub-contractor when they discover "Bodge it Brothers" no longer trade under the same name. They would far rather drag it through the courts than pay a claim.

 

 

As for this part my money is is on this is the reason why a major government contractor from the West Country went through the hoop not to long ago 

They were responsible for many of the hospitals and flats around the country ,IIRC they were the only UK company licensed to use this system when it first come about 

Prevention is always better than cure 

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On 22/01/2017 at 8:57 PM, Mikhail Liebenstein said:

I do think people need to embark on research before doing anything from solar panels, wood chip burners, cavity insulation.

A while back one of my neighbours had his roof jet washed, and another then followed suite.

 

 

We must have half a dozen pikeys come around each summer offering that service. Always have non lettered white vans and number plates with no department identifier on them. Some are actually offering a service, some are just casing your house so they can come back later to thieve everything.

A few neighbours have had their roofs done but as you say, it is stupid. One guy in town had the thieving pikeys on his roof with a big petrol driven jet washer. Gippo #1 turned the spray on and blew himself off the roof suffering serious injuries to his back (allegedly). The householder was arrested by the police because he didn't check the people he employed were registered or paying tax (they are pikeys, they pay tax to no mortal, doh!) and he is now facing a huge compo bill from injured pikey who is going around in a wheelchair for a workplace injury.

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6 minutes ago, davidg said:

We must have half a dozen pikeys come around each summer offering that service. Always have non lettered white vans and number plates with no department identifier on them. Some are actually offering a service, some are just casing your house so they can come back later to thieve everything.

A few neighbours have had their roofs done but as you say, it is stupid. One guy in town had the thieving pikeys on his roof with a big petrol driven jet washer. Gippo #1 turned the spray on and blew himself off the roof suffering serious injuries to his back (allegedly). The householder was arrested by the police because he didn't check the people he employed were registered or paying tax (they are pikeys, they pay tax to no mortal, doh!) and he is now facing a huge compo bill from injured pikey who is going around in a wheelchair for a workplace injury.

Can`t help it but you gota  love the EU :lol:

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7 hours ago, StarsEnd said:

Interesting thread.

Does anybody know what would cause extreme condensation? To the point where most of the windows in a house are literally sopping wet? There is also black mildew forming on some walls.

The house is a 1930s semi.

Is it just the way they were built back them? Short of having to have a dehumidifier on for a couple of hours every day are there any other solutions? Any help much appreciated.

We have a late 1920s house with cavity walls and doesn't suffer mold apart from the odd bit on the windows in the bedroom. Grew up in a late 1900 house, that used to be terrible for mold on the walls if you didn't run the heating all the time in the winter months. House had single glazed old wooden drafty windows and open fire places etc, so ventilation wasn't an issue, issue was down to the walls being solid masonary so condensation on the walls. Not all house built in the early part of the 20th century had cavity wall construction,( even later into the conctrete prefab era) so might be what's causing the walls to run with damp. However even with new builds we get problems where people are drying clothes on aiers in the house which you can't really do, due to the lack of any background air flow.

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I regularly dry all my clothes on the radiators and never suffer condensation.

But, I do not use the timer on the central heating, I leave it permanently on at 20C

Could be that switching off at night causes the moisture in the air to condense.

Leaving it on keeps the air dry.

Humidity varies according to the air temperature. That is why in winter musical instruments dry out because outside air drawn into the house may well be 'damp' at 5C but warm it up and it is a lot dryer at 20C

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16 hours ago, Byron said:

I regularly dry all my clothes on the radiators and never suffer condensation.

But, I do not use the timer on the central heating, I leave it permanently on at 20C

Could be that switching off at night causes the moisture in the air to condense.

Leaving it on keeps the air dry.

Humidity varies according to the air temperature. That is why in winter musical instruments dry out because outside air drawn into the house may well be 'damp' at 5C but warm it up and it is a lot dryer at 20C

I agree with this. We are a bit meaner with a 15c 24/7 stat which in practice produces a range of 15 to 18c. No condensation either, variation is a cause.

Amazing how cheap a 15c temp is to maintain, £43.28pm dual fuel on a four bed. But too cool for most I suspect. Just for the polar bears.

But regarding Stars Ends earlier post, there are some houses where no advice will work and special ventilation systems need to be installed and I suspect installing cavity insulation into older double brick skin houses is the main cause. I have been there and nothing straightforward like opening windows or a temperate climate works. Also worth checking on wider issues like rising damp. Some older houses have plaster that starts at floor level as opposed to a few cm. above and this will cause condensation.

Edited by crashmonitor
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