Insulating solid walls on Victorian property

[Dave W]

Hope this subject doesn't stir up a hornets nest, but I'm looking to improve the thermal efficiency of our soon to be Victorian property. The solid brick walls have been identified as an area of huge heat loss on the house, so I have been reading up on different options for insulation.

Interior insulation. Appears the cheapest option, but quite disruptive, loss of internal space and from my research it seems key to keep a continous vapour barrier against new plasterboard from lower floor , through ceiling, upper floors to ceiling.

External insulation. Was intrigued by the £6k grant from the government, which I have since secured based on approved installation of this system here :- http://www.zestenergysolutions.co.uk/solid-wall-insulation.php . Total quote is £17k, meaning I would have to fund £11k myself. I have raised concerns around breathability of walls with the installer, but have been told the system is breathable. It passes the building controls regs of Uv of 0.3, so would make for a very comfortable house to live in and a clean painted render finish to outside.

Just wondered what people's views are of the external wall insulation please ?

Dave

 

[Moo]

I never thought I'd see the day when I'd say this, but I'm really interested in the idea of a grant to subsidise external insulation.
Before everyone throws up their hands in horror and demands my expulsion from the forum, let me explain:

Our house is a (very) little terraced cottage, one of those thrown up by the thousand around London at the end of the 19th century, and of absolutely no architectural merit (and, believe it or not, currently worth over three quarters of a million!!!!).
It was not just pebble-dashed, but very badly pebbledashed, and this has to come off. It almost fell off the front of the house (hurrah!) but is stuck so firmly to the back walls that all the bricks will be so badly damaged that the only solution is to re-render.

"No problem," I hear you say, "just lime render, and it will look lovely and the house can breath."

That's what I thought two years ago when we moved in, but -

In this neck of the woods lime plasterers and hens' teeth are almost synonymous;
At our age our pot of gold is small and finite (no more oldies to drop off their perches, no realistic hope of earning anything useful, and definitely no hope of borrowing anything);
We've spent quite a bit de-damping the inside - lowering ground levels, new suspended floors.. - and doing the basics like new heating, wiring, kitchen and bathroom, not to speak of the the acres of cupboards and shelving that had to be installed. (Don't believe anyone who tells you that downsizing will be cheap!);
If we were to find a lime bloke, we'd have nothing left in the pot to pay for our care-homes.

So it's going to have to be cement render, and even that won't be cheap.
Which is why the mention of grants made me prick my ears up.

Please, tell me more!

 

[JoceAndChris]

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[malcolm]

English Heritage have a good pdf on the subject http://www.english-heritage.org.uk/publications/eehb-insulating-solid-walls/eehb-insulating-solid-walls.pdf

I have to insulate my walls. I'm doing internal insulation with cork board and lime mortar. It'll be breathable inside and out which makes it less reliant on a perfect vapour membrane. I was put off by any form of wall waterproofing by the exterior paint which had cracked, saturating the bricks.

Worth checking payback. Ours will be about 125 years, while the insulation is unlikely to last for that long. So it's not environmentally friendly for me to insulate the walls (but building regs require it so I have to do it).

 

[plasticpigeon]

Moo, it's a real shame that you say your house has no architectural merit. It may be one of many but it is attractive, and has a darn site more architectural merit than most places built in the last 60 years. Streets of well kept terraces look lovely, and when people decide they are not special and bash them about the look of the area goes to rot. I understand the reasons you give, and thankfully the front of your house can stay brick, but this disparaging term "no architectural merit" has been responsible for the destruction of most of the attractive buildings in the city where I live.

As far as insulation goes, 11k sounds a lot. Do the numbers stack up. How much would you save a year and what is the payback time. I also don't trust these products or the people who install them, companies will say anything to sell stuff, and don't consider the damage that could be done to the building. If insulation is paramount, may I ask why you bought an old house?

 

[88v8]

As far as insulation goes, 11k sounds a lot. Do the numbers stack up. How much would you save a year and what is the payback time. I also don't trust these products or the people who install them, companies will say anything to sell stuff, and don't consider the damage that could be done to the building. If insulation is paramount, may I ask why you bought an old house?

Hear hear.

That £11k could be invested at 7% net to a basic-rate taxpayer, so that's £770 you have to save every year before you start reckoning the 'savings'. Taking account of the lost opportunity to invest, the payback time is never. Never.

Would it make the house warmer - yes, but one shouldn't kid oneself that it's in any way economical. And as regards the OP, external insulation is totally destructive of architectural detail, might as well be a modern box.

Ivor

 

[Moo]

I'm not bothered about the insulation. It's just that I hoped that a grant would make it work out cheaper than straightforward rendering, but it seems not.
And I'm hoping that by economising on the back extension, which has absolutely no period charm (flat walls with a few windows stuck in) I'll be able to do a proper job on the front, by getting the damaged bricks sorted, having the whole lot re pointed in lime, and restoring some of the detail to the stonework. And replacing the horrid windows with proper sashes, of course.

 

[Flyfisher]

A 7k grants sounds nice but forget that and consider the 11k of your own money you'll need to spend and, as mentioned, work out the payback period from fuel savings . . . Except there'll be a lot of guesswork because fuel prices are only going to increase and the actual heat savings will only be a best guess. I'd be very interested to hear more about 88v8’s 7% investment return though!

It's also an effectively irreversible thing and breathability issues may not reveal themselves for many years. Can the installer give you any references to houses where this work was done 10 years ago so that you could talk to the owners about their experiences with it?

I'm beginning to think that the cheapest form of heating is to spend the winter in Spain!

 

[Dave W]

Lots of good advice, so thankyou.

Regards getting a grant, just do a google for "green deal". Would post a link but I'm moderated at the mo being new :wink:

Regards payback of the £11k , fully agree it takes too ling to make sense. It's more around having a comfortable living environment, so the thought of external wall insulation allowing the existing walls to act like huge storage heaters was very attractive. Also the external brickwork isn't perfect and needs reprinting, so also thought I was killing 2 birds with one stone

However after reading above points, and following some of your links provided, I can now see why alarm bells should be ringing. Need to some intense research now then, as I'm having the whole house rewired in 3 weeks time and need to know if applying internal wall insulation , as it impacts sockets on the outside wall plus repositioning of rads etc.

Thanks again for advice

 

[Dave W]

Phil really is the expert when it comes to plasters and renders, (http://www.philipgaches.com/#!) and he said he didn't trust the stuff, and would need to see its performance over the next 20/30 yrs to judge it.

Unfortunately can't view his site on ipad as needs flash installed. Will have to get to a PC to view , but thanks anyway.

 

[Feltwell]

As a fellow Victorian house owner....

To me wall insulation is a no-go. Internally, it would take away the character that I loved about the place - no way could all the cornices be removed and reinstated without damage, not to mention having to deal with fireplaces, skirting, architraves etc etc. Externally it would take away the character of the brickwork detailing that I so loved about the place, not to mention how do you deal with window reveals, doorways, stone cills etc etc. The only way I would consider it is in a place that had already been so badly bashed about that you wouldn't be doing any additional harm - but even then breathability would be a concern, and the sums on payback would definitely need doing.

Here, I've concentrated on what can be done without changing the character of the house - so the boiler died and was replaced with a much more efficient one, when we replaced the roof I put as much insulation in as I could and I am gradually lining under the sloping attic room ceilings with insulation, plaster boarding and skimming - a compromise, but the original lathe and plaster ceilings are still in place if anyone ever wanted to uncover them, badly cracked as they are, and aesthetically there is no change save for a slightly lower ceiling. I've crawled round under the suspended floors on the ground floor and stuffed insulation in between the joists, and I'm gradually overhauling the sash windows, sorting out the rot and neglect but also machining in brush pile strips that both act as draft proofing, stop them rattling and make them a lot easier to slide open. I'm leaving them as single glazed - no way to do double glazing without compromising aesthetically, and I'm not convinced on the payback either.

All this is making a noticeable difference compared to when we first moved in but it still could not be called a warm house by modern standards, and it is expensive to heat. However, you get used to it, and the measures I've taken should have reasonable payback periods or are coincidental to other works that need doing anyway.

 

[jocelyn plummer]

Government Grants and approved installations ---who is scratching whose back?

Really, would not even be interested in that.

 

[88v8]

... I'd be very interested to hear more about 88v8’s 7% investment return though!

LLPC, LLPD (dividend)
LB2N, BOI (interest)
There is other Fixed Interest in the 6% range, such as AV.A, AV.B, ELLA, GACA, RE.B, SANB, etc (dividends).
http://www.fixedincomeinvestments.org.uk/home/fixed-income-prices-and-yields

These are tradeable instruments so one's capital is at risk.
And I am not an investment adviser.
But I have money in these, and also various high-yield shares of which much more on the TMF HYP Practical Board. Overall, I have a net return of around 6%, basic rate tax paid. It all helps feed the money-pit that is the Period house

Ivor

 

[Dave W]

So after lots of good advice on here and lots more research on the net, the outside insulation option is being ditched.

I still want to consider some form of insulation, more for comfort than fuel costs (although lower running costs are useful)

The house is about to be rewired in 2 weeks time, so I need to make a decision on internal insulation to walls or not. I only have a picture rail and skirting in majority of rooms, so easy not to lose any key features. Rooms are big enough to take the hit on losing some floor space.

I'm trying to establish if current plaster on wall is lime or not. If latter I assume it would all have to be removed before any insulation is added, otherwise it won't be able to breathe ?

What are people's recommendation for an affordable breathable insulation finished off with lime plaster, please ?

Dave

 

[worms]

The house is about to be rewired in 2 weeks time, so I need to make a decision on internal insulation to walls or not.

Could you ask the electricians to make sure there is six inches of free play in the wiring to each socket so that you have space to accommodate insulation at a later date?

 

[Dave W]

The house is about to be rewired in 2 weeks time, so I need to make a decision on internal insulation to walls or not.

Could you ask the electricians to make sure there is six inches of free play in the wiring to each socket so that you have space to accommodate insulation at a later date?

Good point. Will do this.

 

[Dave W]

Double post.