Insulation
I've concentrated primarily on external insulation here because:
- we started looking at old buildings
- we bought a 1990 vintage house with minimal insulation
- it seems prudent to insulate around concrete or steel framing to avoid cold bridges
- keeping the mass inside the insulation provides thermal inertia
The cost of adding cavity insulation is lower, but special care will be needed with the framing.
ETICS is what we call EWI - external wall insulation - in the UK. It is also referred to as 'capoto' or 'cappotto'.
It seems it can be a lot cheaper than we would expect in the UK if you are doing new-build. I suspect it is cheaper for renovations as well but the price will vary depending on how many period features you are trying to retain (or emulate) and the way that you move windows, window stones etc and handle the roof overhangs. For new build, you can expect to get ETICS for ?40-?80 or so over the base costs of framing and filling the wall with bricks.
ETICS systems need a glue/mortar substrate and also mechanical fixings, and they typically have a base coat and mesh before the plaster layer. They also need a base rail. It seems that some installers are economical with the base rail, or the mechanical fixings, or the mesh that needs to be installed into the render layer to protect the insulation against impact damage.
Very approximate prices excluding delivery and fitting. Please let me know of corrections here. Take these with a pinch of salt, and remember that they do not include IVA.
I believe that the fixed costs for the base glue etc are about ?26/m2, and that there is a variable cost on top of the depth of insulation of about ?0.10 per mm from mechanical fixings.
Don't plan your budget on this without verifying. Assume I made these numbers up to mislead and confuse.
| Material | Lambda | Raw Cost, R1 | Approx. Installed cost, R2 |
|---|---|---|---|
| PUR | 0.023 | 8.50 | 47 |
| Neopor | 0.031 | 3.00 ??? | 39 |
| EPS | 0.037 | 4.00 ??? | 41 |
| Rockwool | 0.036 | 5.00 ??? | 43 |
| Black Cork | 0.040 | 9.45 | 54 |
| Weber Aislone | 0.042 | 23.00 (but see below) | 55 (for R1.8) |
| Multipor | 0.045 | 13.50 | 60 |
Notes:
- Lambda is a measure of thermal conductivity. A low lambda value means that you need a small depth of insulation to provide a given level of thermal resistance, R. In practice you can read a lambda of 0.036 as '36mm to provide R1.0'. Resistances can be summed, and the reciprocal of the sum is the U value. I find working with resistances more intuitive than with the overall conductivity (U value).
- The proposed insulation standards for Portugal are evolving and the combination of thermal bricks which provide R1 and an ETICS solution that provides R2 would appear to be adequate (with U0.33) for Lisbon (but not Braganca) through to 2021 and beyond. I'm not sure what this will imply for Tomar. Furthermore, the value is between the U values used in Passive Houses for South West Europe for Lisbon (U0.62) and Porto (U0.202) and similar to that for Seville (0.353) - the value is already adequate for a mild climate if other issues such as ventilation management and thermal mass are addressed.
- The very rough cost estimates are for 'modest' depths. If you add a lot of depth then you may have extra costs relating to windows and doors (and shutters).
- Aislone is applied as a putty by hand or by machine and does not seem to need the same glue and mechanical fixings as rigid boards,. It seems cheap compared to lime/cork products, at least for a single-layer application.
- The Black Cork insulation price above is the raw board cost from Corklink. It seems very cheap to me, I haven't been given the impression that products from Amorim are that cheap. Whether they are equivalent is another matter.
- The EPS price is based on price at Leroy Merlin for a 40mm EPS board and a second-hand look at a quote. The material is very cheap in the UK as well. However, I suspect that it can be bought cheaper - there is no sense in it being more than Neopor. EPS performance and price seems very variable.
- The Neopor EPS-G price is loosely based on a pricelist I was sent. It really is that cheap.
- The Multipor price is based on 'about ?300/m3 delivered but not installed' which I estimated from various online resources. It has good fire resistance and is supposedly breathable.
- I have second-hand evidence of an 80mm EPS-based ETICS less than ?40, and for an unspecified 100mm ETICS layer over LSF at ?35. If anything the estimates might be conservative.
- Before getting carried away with excitement, note that this Previcon product apparently provides brickwork and 'lost formwork' for framing and U0.36 and is supposedly about ?30 per square metre of wall. It seems almost too good to be true: there may still be a case for using an insulated render around the outside to reduce the thermal breaks from the mortar beds and to improve airtightness.
PIR boards with lambda 0.023. ISOETICS is quoted up to 60mm depth but the boards can be made thicker and standard sizes for the floor insulation goes to 80mm. The compression performance is 250Kpa (also 250kN/m2). However the ISOWall produucts are much bigger boards and have 'half joint fitting system to avoid thermal breaks'.
Manufacturer of EPS and Neopor board, including an ETICS system. It is unclear how thick they can make the boards. The value after 'Neoplas' indicates the density.
Manufacturer of graphite-enhanced EPS (neopor) with lambda 0.32. This system is really rather inexpensive - even EPS100 density is less than ?120 per cubic metre plus IVA and delivery. I have no idea whether other Neopor stockists will have similar pricing.
Mineral-wool ETICS system. Depths from 60mm (R1.65) to 140mm (R3.85).
The range seems broadly similar to Knauf and Weber, although technical information could be more forthcoming.
Assorted systems, the best performing one is XPS - there is no PUR (or PIR) system. This should be widely available - the 'thermal bricks' offered by various Portuguese manufactorers as 'tijolo termico' seem to be licensed Leca product developed by Weber and some brick manufacturers specifically mention Weber ETICS systems.
This looks an interesting product to me, especially if the breathability is appropriate and you can install it yourself (or get a spray application), since the insulation performance is better than the insulating lime and cork (or lime and expanded glass) renders - and its not ruinously expensive. If you sign up for the download area at Artebel then you find that they quote whole-wall U values by using Aislone to augment the resistance of the thermal blocks. It may be good value at 40mm, particularly if you can apply it yourself and you have a basic brick and concrete structure since the fixed costs relating to the mounting are at least partially eliminated: it should double the thermal resistance of a 200mm brick wall with concrete pillars with one 40mm layer. Priced based on 3cm thickness from one bag, based on this. Max depth is 80mm, and a reinforcing mesh is needed at 40mm and the material is relatively expensive, so the price advantage from simpler application may be partially lost at thicker depths.
Discussion suggests that a 6cm covering of Aislone will cost about ???40/m2 plus IVA, and 25/30 for 4cm.
A Portuguese sprayed external insulation with embedded EPS; the claimed thermal conductivity is 0.070 compared to Aislone 0.042, but it might be cheaper - although it would have to be quite a lot cheaper to make up for the poorer performance. If you want to improve airtightness and take the edge of thermal bridges, then it might be enough. In this (from 2010) it seems that about 4cm layer would cost about ?30 installed.
Lime render with cork granules, it is supposed to be very good at letting moisture escape. There are a number of similar insulating renders from Italian companies like this, this, this or this. The Portuguese market is handled out of Diasen's Export Office by Francesco Marcelli. The local partner is Largemind (Dr Manuel Caleiro). I believe there are (or were) similar Portuguese products such as Suberlyme but the web links seem broken and unmaintained. The price here suggests that R1 is about ?36 or so, (more if you need a bonding or preparation coat). The cost in Portugal is about ?13.50 per centimetre depth.
Another insulating render - this time with expanded glass granules. I believe the Turkish manufacturer has no Iberian distribution but they were happy to quote ex-factory - and it seemed rather cheaper than Diathonite, though I'm not sure about Aislone. It used to be advertised in the UK at ?12.50 per 8kg bag, which gives coverage of 1m2 at 20mm. Perhaps ?900/m3. It looks like it might have a tanking application too.
Another Italian insulating mortar - this time designed for 'thermal insulating fluid mortar, also applicable to variable thickness on horizontal, inclined surface and interspaces`. It looks to me that it might be useful for flat roof systems or a screeding. The Portuguese partner is apparently Petibol Embalagens De Plastico. I have no idea how much it costs.
Lightweight breathable mortar, lambda 0.068, reasonable compressive strength, contains lime, perlite and glass. Seel here as well.
Autoclaved ulta-lightweight concrete insulation blocks from Xella, with lambda 0.045. Not cheap - they are made in Belgium. They can be plastered directly. Like rock wool they are fireproof and apparently breathable. I believe that the 120mm blocks are about ?35/sqm and the 140mm blocks are about 443/sqm, delivered - the block price seems based on material volume and in effect the cost of transport is too, so about ?300/m3 delivered but not installed. Contact.
Ecoplace sell a variety of Celenit boards, but I find G3 the most interesting if you do not need breathability since it uses Neopor: the 75mm deep board has R2.2 and I believe it will take render directly. In the UK, very similar boards are also available from Savolit. Apparently, there is one source for the machines that make these boards, so there is little to choose between various cementitious wood wool products.
Refreshingly open pricing on cork boards. Its not clear on the web site - but the boards are the `standard' 1m by 0.5m by specified depth, square edge.
Cork and coconut products for insulation. I don't know how much they cost, but this seems like a full ETICS system and that may result in a premium over Corklink. There are two parts of Amorim of interest in building: Amorim Isolamentos make the ETICS product and MDFacacde, and Amorim Cork Composites who make an interesting product called Corkwall (sold in the UK through Corksol). Its not an insulation product per se - but is interesting as a through-coloured sprayed render which looks to have valuable breathability and flexibility, so it might be useful as a final finish on breathing walls that would otherwise need painting.
If you are doing a newbuild construction, then it would be hard to see a need for this. But I could see it being useful for certain renovation projects where you can retain period features iff you can keep the insulation depth to a minimum. The lambda is between PUR and Neopor (0.028). And, if you can convince fixit to supply you, it is expensive. If you can afford this, then you might be better off shopping for a couple of layers of Aerogel blankets with mechanicsl fixings.
Cellulose fibre insulation, 'impregnated with mineral salt' to 'protect against fire, mould, insects or vermin'. I believe the normal impregnation is borax, and this seems to be poisonous to termites.
- Isorenel is an installer for a veriety of insulation products including
- Icynene
- Isocasa injected foam for cavities
- blown cellulose fibre insulation
- high performance spray foam roofing system
Cellular glass insulation, that can be used below ground as perimeter insulation. Some of the boards can be used to bear the load of masonry walls: its not clear that they are strong enough to bear the load of a concrete pillar. Perinsul HL compression support is >= 2.75MPa. Expensive - look here for UK pricing.
Foamed glass ETICS with lime). Waterproof, rot-proof. It might be a system product based around Foamglas.
Not an insulation product per se - but an interesting mortar for attaching EPS and Cork. Elastic and water repellant.
I first saw this here. I don't know how much it costs, but it seems useful for the suggested thermal-bridge reduction, particularly if you are paranoid about termites. For example, it might be useful in LSF construction to isolate the frame from the external skin and facade insulation, although doing so might destroy any cost advantage that LSF can bring.