Dafty

Does anyone have any experience with retro fit external house insulation ?
We installed pvc double glazing and doors a few years back and that did make a difference in both summer and winter, but with single skin construction, a vast amount of heat just disappears through the walls in winter when in can be chilly and damp, even in Algarve !
Be interested to know of any experiences of "Cappotto", or the like

Johnboyuk

You can get this product in the UK. I am sure there is something similar in Portugal.

External Wall Insulation | ECO Scheme | Sheffield, Yorkshire (allseasonsinteriors.co.uk)

liveaboard

It's a regular job that builders do here; They attach PU foam board (DuPont wallmate or similar) to the outside walls, put a fiber mesh over it, and then plaster it with concrete (stucco) so it looks like a regular concrete wall.
The tricky parts are the doors and windows, edges and trim.
It's not a cheap job, 10-20,000 for a medium size house.
Sometimes it goes wrong and falls off!
But usually it works just fine. I've seen it done a few times.
The alternative is rockwool/ fiberglass on the inside walls, then finished plasterboard. also a big job, but will work and look better.
I did my floor and ceiling inside, never got around to doing the walls.

wellinever

Echo what Liveaboard says for older houses insulation on the outside will of course insulate, but really made for modern (new houses) where it is combined with a single 20/25 cms tijolo. Of course this is added to bare tijolos, and not fixed to existing exterior render,
Sometimes a thermal tijolo which is much better than the normal 15cm is used. (See Preceram)
My own opinion is that if not done absolutely to the instructions, in the right weather conditions it would insulate but could give rise to issues down the line.
Insulating the inside has advantage of insulating from within rather than without, so the walls stay cold but inside is warm.
Also I am not convinced that this insulation method will be without probs after 20 years or so, with the heat of summer in Southern Europe..
Of course more messy done inside.
Look at cost and consider efficient AC for heating instead, against quotes for doing inside and outside. Maybe consider underfloor electric heating at 100w/m2 so a 20 mtr room would be using 2kw/H......about 30cents/hour with thermostat and good insulation, easy to do, get a change of floor in the process (tiles or wood laminate).
May not provide all the heating neede on very cold spells, but underfloor heating does give a very good background heat which makes you feel comfortable. (Buy in UK if poss)

Johnboyuk

Thanks to all. I am looking at a renovation so I need to get it right. The methods for the floors and ceilings are clear, I was looking at insulation backed plasterboard for the walls. Then there is the North American method with studs fitted to the walls and the voids packed with insulation and a vapour barrier. I think this may be the method liveaboard is referring to? This could also cause substantial work when finishing around doors and windows though.

liveaboard

Yes;
the material seems to be getting more popular here, I noticed a small local building supply is selling it now.

Advantage is that the internal finish will be very good, and you can put in all your wiring easily at the same time.
Disadvantage is loss of space; 7-10 cm from each side.
Major advantage, acoustic deadening. These hollow brick houses carry sound from one end to the other as if that was the design criteria.

Put water underfloor heating if you can. This can only be done during major renovation; it's expensive, but once it's done you can upgrade / change your heat source easily. It's fairly future proof.

A big problem with exterior wall insulation is that heat still escapes through the masonry at the top edges. That means cold upper corners inside, which causes condensation formation and mold.

Another tip; heat recovery ventilation.
I installed a HRV unit in our house 10 years ago, it constantly renews the inside air without significant heat loss.
Most people just get used to the moldy odor of old masonry houses here. That doesn't mean it's not a problem.

Wellinever suggested to "Buy in UK if poss"
I think we all know that is a terrible piece of advice.

wellinever

Really???.....I installed electric underfloor heating in my new build, (2 years ago) complete with all thermostats. Took the builder 10 mins to roll out the membrane in each room, total cost was €350, against price in Portugal of over €1000, and when it appeared that one of the thermostats was faulty, the UK company simply sent me a new one FOC and arrived 4 days after my email them, on my inspection to replace the faulty one, it turned out that the builder had wired the original one up incorrectly so now have a spare.
I personally would not put water underfloor heating, way to many things to go wrong, in Portugal. Electric at €0.15 per 10sq mtr of floor (100kwH/m2 ), takes no more than 15 mins to sense the heat in mid winter from a cold start.....so I am more than happy with it...
But each to his own

Johnboyuk

I came across these solar powered ventilation/dehumidification units. I am not sure if they can be used as a primary source of heating but look worthy of further investigation. The noise factor that liveaboard mentioned is also worth rembering as I am sure that it is something that many, including myself, do not think of.


I must say that having returned to the UK after a long absence, I am impressed with many of the small private builders here and the DIY market in general. Many of my neighbours have had quality extensions built at very competitive rates. Like everywhere, the cowboys exist but it is reassuring to know that it is not everyone.

Rambling archer

I think you may have forgotten the consequences of Brexit and all the extra charges on importing from the UK, not to mention delays and hassle with admin/customs/transport ... two years ago is no longer relevant to the current question?

wellinever

The point is I personally would use underfloor electric underfloor heating rather than water based system.
I have looked at Leroy Merlin and they now DO stock a range of underfloor heating rolls, and Stats....for example:

https://www.leroymerlin.pt/Produtos/...R_REF_82303338

Midgo

We had Capoto put on our 40 year old classic reinf concrete framed house in Costa Caprica area about 3 years ago
Very happy with it indeed, lovely warm dry house with our pellet burners and aircon/het pumps upstairs (floors are thick concrete so needed something upstairs for a boost in winter / summer)
The foam needs to be physically held to the wall via plastic 'top hat' fasteners, not just glue
Window sils need to be extended etc

BillBullock

Did the roof tiles need to be extended to cover the top of the Capoto? Mine would need this along the sloping edges.

Midgo

Nope, they extended far enough
But on some walls there are no tiles (parapet-type) and the top of the wall was sealed over.

clyttle

Good to hear My house sounds similar and is freezing and I'm really interested in capotto. Do you have a company you can recommend that you used?
Also do you have a rough price for a job like this?

J00ls

Seconded. We loved our electric underfloor heating before we moved. Provided you have the Tilers lined up ready to put the floor down plus good quality controls, it’s a no-brainer. We were warned off using water pipes in areas that suffer earth tremors.