14/08/2014

How insulate thermally and acoustically easy and economically your housing

 How insulate thermally and acoustically easy and economically your housing

Insulating materials; polystyrene extruded and rolled sponge
As already discussed previously on this blog, isolate housing is one of the best investments that can be made today, by welfare, economy and health.
In most of the houses in Spain, an incredible amount of heat is lost due to their bad isolation; a well insulated House heats up very little energy and better maintain the temperature.

Much of the heat loss occurs over the roofs (especially if they are not downloaded with insulation) first, then by the walls and finally on the ground, in that order.
In this entry we will see a way to isolate ceilings (acoustic and heat; so that we do not disturb neighbors with noise or disturb us, in addition to saving energy), and we will see also a wall how insulate thermally inside losing just 3 to 4 cms.

Insulation options

Earlier we saw that the best is to fill air chambers with some cheap and durable insulation as the injectable cellulose treated with borax (the cheapest and effective currently) salts, however sometimes there is no air Chamber so we have to apply insulation on the inside, reducing some space in the room but winning much in economicscomfort and well-being, as we shall see below.

Deciding for one or another insulation we have multiple options for different needs and different prices; a good thermal insulator is usually not so good acoustic insulation and vice versa. After assessing different opcionnes, the best choice in terms of price and effectiveness is a mixed solution of thermal and acoustic.
The insulation work by limiting the movement of the air in any way, to slow the transfer of heat as much as possible.
The best acoustic insulation are flexible materials (rubbers and similar) absorb the noise to the cushioning, and tend to have good thermal properties. Flexible materials with air inside Chambers are also good sound insulation.
  • We have chosen extruded polystyrene as insulating material for being cheaper than other materials (such as fiber glass or rock wool), with very good thermal insulation and acoustic insulation to keep in mind; about €3 plate 1200 x 600 of the M30 chovafoam of 3 cms thickness (without the intention of doing advertising, they have acquired at Leroy Merlin). Durability (over 100 years), resistance and lightness are other advantages, that will allow us to place the rafters directly over insulation.
  • Another option to consider (but I have not seen in Leroy) are the planks of wood fibres, economic and good insulation thermal and acoustic, which often come treated with fire-retardant to slow combustion.
  • As acoustic insulation for its price, effectiveness and lightness have chosen sponge rolls, 2 cm of thickness, that place between the insulation and the plasterboard.
  • Yes we don't have very limited budget, it is best to use wool rock or glass in rolls; It has good permeability of water, non-flammable (endure up to 1000 ° C), and reduces both thermal transfer and the sound, giving very good results in the majority of cases.
  • If you have a budget very, very limited, as acoustic insulation can use pieces of mattress, rubber, even old clothes of cotton or similar...  options.
  • In is page we have a very good relationship of thermal insulating options and recommendations.
Both the sponge and polystyrene are flammable materials, but they will be protected from sources of heat (do not serve to isolate sources of heat above 100 ° C) by plates (popularly known as plasterboard) plaster that will cover them (which in addition also has good insulating properties), it is cheap, easy to work and very resistant.
Attention: If your House is very wet because it has a source of moisture in the soil (is a bass or similar), or sponge and polystyrene would be most advisable; It would have to replace those materials with a breathable insulation (as the Rockwool roll or similar - but not water-resistant foil-) to allow moisture to escape abroad. It depends on where it comes from moisture; If the wall to isolate is the source of moisture, then it we could use these materials as a barrier to moisture. I recommend you read this entry on moisture and possible solutions.
After squeezing me the link looking for the best way to put them, I found the solution; using index long nailable tacos I place floating above the thermal insulation chovafoam rafters of wood where the plasterboard is screwed, and in the space of 25 mm. between the drywall and insulation, to introduce pieces tailored to acoustic insulation (also wood can be replaced by metal profiles).

Necessary material
Before buying the material or perform any action, it is advisable to consult your Finance Office how tax deductible in the income improvement, which has increased in the Royal Decree Law 5/2011 20% of the work (to encourage this type of performances); Since this type of work have by object the improvement of energy efficiency, hygiene, health and protection of the environment. For other cases, in the State housing and rehabilitation Plan can consult them.
We will need the following material to carry out the work; the material for 10 m 2 each room has cost us about €200.
  • Extruded polystyrene plates 1200 x 600, there are of different thicknesses, which you prefer according to what we can lower the ceiling; needed some 13 of these measures for 10 m2.
  • Rolls of agglomerate of foams and elastomers high density acoustic insulation (e.g. Copopren), there are also sheets; I've seen them green and black; they are very similar, only change the color. I've spent 4 rolls of 3 cm. thick by 10 m² bedroom, but it will depend on the size.


  • Wooden battens at least 10 cms wide to have margin to screw the plasterboard (can be replaced by veneer for plasterboard profiles), and minimum thickness according to what you have acoustic insulation; the sponge was 2 cm of thickness, so cheap slats for wooden treated 2000 garden were acquired long x width 120 x 25 mm. thick, so make sure its long moth:


  • Plates of plasterboard; to be manageable by one person we acquire 1200 x 600 mm x 10 mm. at Leroy Merlin; It should take into account that are cut so not have the recess on the sides to finish the joints so it is not suitable to use fiberglass mesh and then queue for drywall to cover them, but it is best give the tail just to cover the screws and joints and then sanding with a Sander orbital or similar only where necessary by excess.



  • Nailable plugs 8 mm x 80 long (the length will depend on the thickness of the insulation; (they must have the same size than the sum of the thickness of the tables, the insulation that will be glued and add 3 cm more than they will be tucked in the ceiling); they are very quick to use; just give a blow of cock so that they are set by holding the wood battens. Those who buy are brand Index, but surely you like other brands. Head carrying the plastic prevents that pass the wood and to leak inside to hit; they are very comfortable if you only have two hands ;) and avoid tightening the screws unevenly and that left us highlights in slats:

  • Lag screws countersunk head of plasterboard of 25 mm long; enough that it caught in the rafters. A box of 500 accessible for 3 rooms.
  • Translucent silicone tubes to glue polystyrene plates.
Keep in mind that your need may be different; This is a solution for low ceilings; If you have high enough you can apply more insulation thickness; for example 4 or 6 cm of polystyrene and 1.5 cms instead of 1 cm on plasterboard, and the same with foam; nailable plugs will have to catch them according to total thickness + 2 or 3 cms that will be nailed to the wall.

Necessary tool

Without the right tool a well finished job is not possible; we will need an artboard (two stands and a wide table) where to cut the material to size, wood, screwdriver Cordless saw, jig saw blade (cutter) sponge, one or two ladders folding to move by room, an auxiliary Phillips screwdriver, Sander with 80 or 120 grit sandpaper to finish off the tail of the plasterboard dry oncea drill with drill bit 8 of wood and the other long (150 mm. at least) to wall for 8 (of vidia) taco, a hammer, silicone gun, a measuring tape (metro autoenrrollable) and an extension cord if we don't have outlets near.


Now Get to work

First place the extruded polystyrene, which due to its characteristics (resistance and lightness) will allow us to place over the battens, supported it, but as if They were 'floating', without tightening them too much.
This has occurred we paste them with silicone. The silicone may not be enough to secure them to the ceiling, so it is necessary to hold each plate with at least one screw; We can use the countersunk head nailable plugs, which then withdraw once placed the battens.

The plates have unions shaped H that improve even more insulation there are no separations, however small that are. You start in a corner and we glued, place and screw one by one.


Arriving at the remaining corners we will have to cut pieces to the extent necessary and will follow the same procedure.


Once the thermal insulator, prepare the battens to practice holes approx. every 30 cms where we will place the nailable plugs, starting near one of the corners. In small pieces we also give out no holes so that the corners are tight and do not lift by placing them.
We put them to take account of the drywall joints are in the center of these battens, in this case to 60 cms, knowing that the table on the side of the roof will leave less hole in the Center to place the acoustic insulation.
Update 17/01/13: professional installers recommend put battens every 50 cms and conversely, to produce plates de forma que las placas queden are subject also by the Center. I have done so to simplify work. However I had no problems of warped the plasterboard by placing to 60 cms.
Thanks to nailable, tacos we can present the Batten in place, helping him to carry out one of the holes with the drill and bit long vidia, introducing ceiling enough to engage fully the taco to flush with the wood. With a couple of hammer will be securely and without pressing too much insulation:


Where the roof present irregularities, rafters allow us to hide them, so it is convenient to buy them as straight as possible.
We screw, as shown in the pictures, plates of plaster with the countersunk head screws inserted until they are flush without breaking the plasterboard; 2 cms away from the corners and about 20 or 30 cms of screw a screw; so it is very convenient to use a flat blade screwdriver battery with regulation of torque (so the limiter jump to reach the screw head flush).
To save work we can put the pieces of insulation acoustic of 2 cm. thickness whenever we put and atornillemos a layer of plaster in the hollow between the drywall and insulation glued to the ceiling. As the battens are 0.5 cm. wide you provide placement, cutting them tailored to the hollow.


For the last sections there where you can not enter insulation sponge, always we can screw carefully into the thermal insulation to keep it on your website to put Sheetrock:


If in some final stretch we have no where to attach the plasterboard, it must use ingenuity by placing pieces of table fixed with screws to hold it. To finish the work, we applied with a flexible spatula tail for plasterboard, just enough to cover the joints and the heads of the screws; If done well it is not necessary to sand much later. Surely plasterboard that you use take a zone reduced side; there is where will the union queue; in this case it must be first fibre glass mesh so not to crack the expansion/contraction.
Important: It If you have recessed lighting, insulation will not escape the heat, so it can melt and even become inflamed by the high temperatures that can reach the area of focus. In that case there is to leave an area around the focus without placing insulation; If they are halogen (FMCG) to the less 25 cms. radius around each bulb. If they are low, with about 10 cm. can be sufficient. To make the calculation, we can get an idea to know the Watts consumed at each point, and let a circle of that measure for safety. For 50W = diameter of 50 cm. up to the insulation.


And this is the result once sanded and painted (to hold the lamp again on your website we have placed a box of wooden battens tirafondeados to ensure its holding):


We will have perfectly insulated the roof losing only 6.5 cm. height 3 cm insulating material, 2.5 cms of battens (and acoustic insulation) and 1 cm. of plasterboard, which also has good thermal and acoustic insulation properties, saving lots of energy and without the noise of neighbors fear.

Insulating a wall inside

I will briefly discuss how we have used thermofonic 7 and plasterboard to insulate a wall.

7 Thermofonic: Although good reflective insulation, it is expensive; If we have room we can opt for other isolates that even if they take up more to get the same result, are cheaper.
We did not want to lose plenty of space, so we chose the 7 thermofonic for insulating a wall of moisture and temperature characteristics of thickness and effectiveness; with 7-ply sheets of aluminum and plastic with bubbles it has good features as reflective thermal insulation, but not isolate just the noise.
However, If we didn't have moisture problems, is better to resort to the "chovafoam" of 4 cm. thick similar to that used in the ceiling between Batten and Batten, then plasterboard; We will lose only 5 cm. of space and it will be more economical and similar result (better even sound insulation).
Instead of putting a camera between the wall and the termofonic and plasterboard as suggested the manufacturer, wasting less space to prevent moisture from affecting the battens have placed directly attached to the wall the termofonic with the battens screwed with 60 nailable plugs, and then the drywall screwed to them:

To join the auctions we have used duct tape; resistant and waterproof.
An air Chamber of 2 cm. between the drywall and insulation has been. On the other hand we could have improved insulation also by placing acoustic insulation in the gap, but due to lack of budget and that side was not origin of sounds, not we have deemed it necessary.

To round off the corners we used adhesive fiberglass mesh in rolls of 50 mm. width:


And we have repositioned plugs and switches by placing pieces of Batten leaving a gap for them and by screwing into the tables:


Finally there is the result, in the absence of paint:


"Rustic" otherwise insulate the ceiling

Example of roof insulated with fibre wadding/hemp screwed irons

Example of roof insulated with bolted plates of vegetable fiber; good material if you want excess moisture to breathe to the outside