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Various building/refurbishment questions

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Steve

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Mar 01, 2020 3:55 pm

(@stevej)

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Joined: 14 years ago

Hi,

We're currently getting quotes together for a refurbishment and partial new-build, and are getting conflicting suggestions from different builders. Seeing as most of the issues are outside of our previous experience (either 'cus they are "Portuguese" things, or things we didn't have in the UK) I wonder if anyone could give advice/experiences on these matters.

1) Insulation - we have a single storey house with a concrete slab between the ground floor and the loft. The roof is tiled with timber rafters and with currently no insulation. We do not intend to make the roof-space "usable", and I would prefer to keep the timbers visible for future checking/treatment. So far we've had suggested:

a) Take off all tiles, fit insulation panels on top of the rafters and then replace the tiles on top of the insulation;
b) Insulation panels fitted between the rafters, with possibly also boarding the underside of the rafters;
c) Insulation panels fitted to the top of the slab - ie, the "floor" of the roof-space;
d) Insulation fitted to the underside of the slab, in effect a false ceiling to all the ground-floor rooms.

2) Hot water system - the plans indicate a pumped circulation system, with the heat source being a gas boiler taking water heated by a solar panel. If I understand it correctly, this should have hot water circulating all the time, so we get instant hot water at the taps. Saves water, but will it be heavy on gas and electricity for heating/pumping?

3) Indoor pool (concrete construction):
a) Salt or Chlorine?
b) Vinyl-lined or mosaic-tiled?
On both of these aspects, we've had strong recommendations for each option.

Any comments greatly appreciated.

Thanks,

Steve

8 Replies

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hartmill

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Mar 02, 2020 2:41 pm

(@hartmill)

Estimable Member

Joined: 13 years ago

Can´t answer all your questions, but I had a concrete mosaic pool built around ten years ago. Almost immediately small tiles started coming off. I had the gaps replaced with new tiles in the third and fourth year. I then spent a lot of time using glue to reseat individual tiles until the year before last. In 2018 around a hundred individual tiles came off. Last year loads more and it was obviously leaking.It is now going to cost a fortune to sort it out. I will not be using any sort of tiles!!

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jardineira_alentejana

Community Member

Mar 05, 2021 2:42 pm

(@jardineira_alentejana)

Active Member

Joined: 7 months ago

Steve,

I see that you posted this a while back but I'm wondering what you ended up learning and what progress you were able to make, especially given the circumstances of the last year.

We are currently looking into options for insulating our roof and walls, and would be interested to hear about your experience. What type of insulation did you end up installing? Did you also insulate the walls and/or swap out the windows?

What did you decide on for your hot water system?

Thanks!

Christine

Posts: 230

jeannemarie

Premium Member

Mar 06, 2021 5:30 am

(@jeanne)

Estimable Member

Joined: 12 months ago

'RE 1: you need to define your 'conditioned space' . If you do not intend to ever make the space between your ceiling and the roof usable, then your conditioned space stops at the ceiling of your inhabited floor, and you insulate directly above that (but be sure to ventilate the roof space). It only makes sense to insulate on top of the rafters if you are enclosing what will become part of your conditioned space.

if you have no intention of ever using the loft area as usable/conditioned space, I would go for your option C. Option D is also possible, but then you will need to finish it off to a presentable finish, which involves additional work and expense, which is less necessary with option C, where you only need to make certain you have an uninterrupted layer of insulation.

I don't know if vapor barriers are typically installed in PT, but if you do use one, it goes on towards the conditioned space to prevent warm, moist air from condensing on a cold surface (=mold!!).

The insulation will help contain the environment you create under it; if you will not be living in or using the space above your ceiling slab then there is no use in including it in you conditioned, i.e. cooled or heated, space.

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ThomasRibatejo

Ask Our Expats Consultant

(@thomasribatejo)

Joined: 4 years ago

Member

Posts: 390

Apr 02, 2021 5:22 pm

Reply to

jeannemarie

@jeanne absolutely! Option C makes most sense, Option D does the same with more hassle (extra work, redecoration, etc). No point insulating and losing heat into an unused void further up. Mineral wool is common here, sometimes with a thin vapour barrier included (but best to add a real one beneath the mineral wool, to avoid condensation build-up). Insulation panels also fine, of course, depending on availability, costs, and ratings.

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Steve

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Topic starter

Apr 04, 2021 7:50 pm

(@stevej)

Noble Member

Joined: 14 years ago

Hi,

I've only just seen the recent replies to my initial post - sorry.

To answer the insulation question: cost issues mean that we haven't gone for any insulation in the part of the house with the concrete slab ceiling. We have no intention of using the loft space, and probably would have gone for option C - the builders were talking about spraying a foam insulation over the slab. It's an option we can easily return to in the future.

All the windows have been replaced, and we haven't bothered with any insulation on the 2-3ft thick walls.

Hot water: we've ended up with an air-source heat pump being fed pre-heated water from a solar panel. The hot water will be on a circulation system. We dithered a lot on this, but as there is a long distance between the water heating gubbins and the places where we'll use most hot water, we came down on the side of the circulation system so there is no heating miles of pipes and wasting water just to wash your hands (while singing Happy Birthday of course).

Pool - we've ended with a single-pouring concrete pool, rendered and then resin lined, followed by mosaic tiles. It is the system the builder we went with uses - time will tell.

Steve

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jeannemarie

Premium Member

(@jeanne)

Joined: 12 months ago

Estimable Member

Posts: 230

Apr 04, 2021 11:36 pm

Reply to

Steve

@stevej. Depending on what they are made of (stone?), even 2-3 ft thick walls may have a low insulation value. They will certainly have a lot of thermal mass, but that is not the same thing. Windows generally make up a relatively small portion of the exterior of a house. To my thinking, replacing them might make sense if they are cracked/leaky/rotten, but if the rest of the wall area is not insulated, I don't know how much overall difference new Windows make.

If your interior shell is not insulated, make sure to ventilate well during the heating season to avoid condensation issues. Spray foam insulation gives a nice continuous layer, but T/G insulation boards (available in PT?) with taped seams is a super easy DIY project.

Thanks for sharing RE you hot water solution. BTW- is PEX tubing used much for heating/plumbing in Portugal?

I'm happy to be corrected about any of my assumptions .... always learning.

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