# New roof



## Lawrence brown (May 24, 2009)

For some time here in the UK housebuilders have been using pre fabricated roof trusses. The advantage being that they turn up on the back of a lorry and can be put up within a few hours instead of having each piece cut and assembled on site and taking days (if not weeks!) 
Does anyone know if this method of construction is allowed in Spain?
I ask because this would mean that I could have more control of my build, ie no changes in design so that I get what I want and not what the builder wants to build.


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## Lawrence brown (May 24, 2009)

I take it nobody knows, but could anyone suggest where I might find out?


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## xabiaxica (Jun 23, 2009)

Lawrence brown said:


> I take it nobody knows, but could anyone suggest where I might find out?


you might well have not had any replies simply because it can vary depending upon your local ayuntamiento's planning regs - your best bet would be to make a visit to the planning office where you are building

then make sure you get eveything in writing


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## jimenato (Nov 21, 2009)

It's a good question and one to which I don't have an answer. 

I did some roofing with a mate of mine for a short time - he had been a roofer in the UK for years before he came here. He had an idea to start a truss pre-fabricating business over here as he was frustrated with the inefficient way roofs are built here and that fact that so many leak after a few years anyway. It would have cost too much to set up and anyway there would, at least around here, be a lot of resistance to it - they seem to like a tonne of concrete per square metre of roof. As to whether it's allowed, best talk to a local architect or the ayuntamiento, You would probably have to import the trusses.


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## Lawrence brown (May 24, 2009)

I know that is the best thing to do but I am 1500 miles away, I just wondered if they were being used anywhere?
If they are in use in one area, there is a chance of them being allowed where I am in Seron.
I am not sure I really want to use concrete beams and hollow concrete blocks for the roof, I would rather go a much higher tech route.
Just one more example, I said I wanted to have Solar power, so the Architect drew ONE panel on the plans!!! and that was for hot water...


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## xabiaxica (Jun 23, 2009)

Lawrence brown said:


> I know that is the best thing to do but I am 1500 miles away, I just wondered if they were being used anywhere?
> If they are in use in one area, there is a chance of them being allowed where I am in Seron.
> I am not sure I really want to use concrete beams and hollow concrete blocks for the roof, I would rather go a much higher tech route.
> Just one more example, I said I wanted to have Solar power, so the Architect drew ONE panel on the plans!!! and that was for hot water...


that's the thing..........just because they are being used in one place is no indication at all that they will be permitted elsewhere


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## Lawrence brown (May 24, 2009)

xabiachica said:


> that's the thing..........just because they are being used in one place is no indication at all that they will be permitted elsewhere


I know you are right, but on the other hand, if they are not allowed anywhere, then at least I know where I stand!

Just trying to drag them into the 20th century!


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## xicoalc (Apr 20, 2010)

What about your architect? Surely you have someone on the ground in spain dealing with the plans, regs, authorities etc? Cant they make the enquiries on your behalf if you are not here?


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## Lawrence brown (May 24, 2009)

It's complicated!
The vendor is a builder, the contract said that the vendor must ensure all of the permissions are in place for the reform, (we bought assuming they were, but fortunately got that condition put in to the contract of sale, just in case) so he paid for the Architect, not me and he has been the one dealing with it. He is from Argentina and speaks good English, but there have been a few problems with communication. The vendor still has his own plans in mind (He didn't have the money to do it himself) and it is difficult to explain what we want.


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## Mexberry (Dec 19, 2011)

We have a casa in Mexico, where they design and build houses based on Spanish models. The newer builds are using concrete beams ( termites would consume wood), then they are using a re enforced foam between the beams. It is light weight, strong heat and waterproof. I am not sure if they then cover the foam with a thin layer of concrete before they lay the tile, or maybe the tile goes directly on top of the foam. 
It is much quicker and far less heavy than the traditional concrete. The polystyrene type foam blocks are about 4 inches thick, with a wire mesh through the middle. 
Mexberry.


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## jimenato (Nov 21, 2009)

Here, the beams are usually wood rather than concrete and I see no problem with having them made somewhere else rather than made on-site. The problem I see is that the prefabricated trusses I've seen in UK houses just wouldn't take the weight of a Spanish roof - they just ain't substantial enough. Mind you - I'm no expert...


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## tonyinspain (Jul 18, 2011)

Depending onthe builder spanish roofs are fine my house is 18yrs old done with concrete and steel beams and is perfectly waterproof i have lived in it for 8yrs and its fine as for panels you need a minimum of four for a two floor house and 4batteries
Inverter and a backup generator that should cover all your needs
Ps my roof is apex and is tiled looks beautiful from the hills
Hope this helps


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## gus-lopez (Jan 4, 2010)

They must be allowed around here as I watched them building one 8 or 9 years ago. They weren't pre-fomed though , it was all constructed on site & they main beams were about 9" x 3". Constructed by Spanish carpenters, for a Spanish family we used to laugh every time we went past as they always appeared to be consulting the plans for every step but it was done correctly ; 16" centres, diagonal supports, noggins, rockwool insulation filling the whole truss depth, felt & battens, air vents , etc. It took them about 5 months ( ?) before the tiles were able to go on.

My only concern would be , as another poster mentioned , the termite problem. It certainly wouldn't be cheaper here , what with the cost of the wood, unless you were able to do it yourself.


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## gus-lopez (Jan 4, 2010)

P.S. 
Just remembered that we have a spaniard over the road building his house using Insulating Concrete Formwork ( Lego ) 
Similar to these ; 
Polystyrene Building Blocks :: Amvic Insulating Concrete Formwork

Beco Wallform ICF System - Insulating Concrete Formwork System

Reinforcing right through from base to roof ; a lot slower build than traditional as they only laid 6 rows at a time & all the blocks have to be threaded over the reinforcing, 6 meters high !


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## spanisharchitect (Feb 5, 2012)

*Trusses*

Hi,
When using any type of construction method in Spain it is compulsory to comply with the Spanish building regulations. Although this may seem obvious most people when from abroad often wants to import his/her own method of construction because they feel more comfortable using a method they are familiar with.
If you want to use timber trusses the standard to comply in Spain is :
(Documento Básico SE-M Seguridad structural Madera) which can be freely down loaded from: the MInisterio de la vivienda web page.
Código Técnico de la Edificación - Normativa - Arquitectura y política de vivienda - Áreas de actividad - Ministerio de Fomento.
It is important to also understand that Spain is a an earthquake country specially the east coast with an ESM grade of up to 7 or 71/2 grades depending the actual locality.
I hope this helps.
****


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## Lawrence brown (May 24, 2009)

spanisharchitect said:


> Hi,
> When using any type of construction method in Spain it is compulsory to comply with the Spanish building regulations. Although this may seem obvious most people when from abroad often wants to import his/her own method of construction because they feel more comfortable using a method they are familiar with.
> If you want to use timber trusses the standard to comply in Spain is :
> (Documento Básico SE-M Seguridad structural Madera) which can be freely down loaded from: the MInisterio de la vivienda web page.
> ...


Thanks, I am sure it will help, I will check it today.
It is not a method I "want" to use, it's just that being prefabricated, I get to approve the design before it gets built, and when it is erected I know it will be what I want, with the right amount of windows etc, and not what the builder wants to do, ie a method he is familiar with!


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## spanisharchitect (Feb 5, 2012)

Lawrence,
But surely you will decide what you want on the plans and not while building, since doint it that way is a very expensive process. 
Regards

Juan


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## Lawrence brown (May 24, 2009)

The plans are done, most of the work is inside, but the roof needs to be replaced.
The builder is already saying "you don't need that, I will do it like this! it will be ok"
Because I am not able to be around as much as I want, I want to make sure it goes ahead the way it is supposed to.


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## spanisharchitect (Feb 5, 2012)

Lawrence.
It sounds a bit risky allowing a builder to design the roof structure.....but then again it is unfare of me to say so, he might be an structural engineer or an architect!!!


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## snikpoh (Nov 19, 2007)

Lawrence brown said:


> The plans are done, most of the work is inside, but the roof needs to be replaced.
> The builder is already saying "you don't need that, I will do it like this! it will be ok"
> Because I am not able to be around as much as I want, I want to make sure it goes ahead the way it is supposed to.


The problem is that to change a roof you must have the correct permission (Obra mayor). Once you have this permission then you must not deviate or it will not get the required completion certificate.

Please do NOT listen to the builder, I was caught out like this and it cost me plenty in both time and money!


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## spanisharchitect (Feb 5, 2012)

snikpoh said:


> The problem is that to change a roof you must have the correct permission (Obra mayor). Once you have this permission then you must not deviate or it will not get the required completion certificate.
> 
> Please do NOT listen to the builder, I was caught out like this and it cost me plenty in both time and money!


I couldn't agree more with snikpoh...You must have the correspondant building license before you are allowed to start work and should not have any changes that can not be reflected afterwords on the plans specially structural changes.
This doen not mean that you can not change anything during construction, you can, but whoever does the changes should know what he is doing.
Juan


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## jojo (Sep 20, 2007)

All I can say Lawrence is that Spain is infamous for its building laws and its ability to demolish properties that dont adhere to them or have the correct permissions

Jo xxx


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