View Full Version : How to raise the roof.
5th January 2010, 01:17 PM
I'm planning a face lift on my house and would like some feed back.
The house is 5 years old and a H shaped detached bungalow in the countryside. Roof is smooth concrete tile / felt / 7x2" rafters / 9x3" joists. Walls are standard double leaf with 4" cavity - insulated in the cavity and internal leaf. Attic space for future conversion but only floored.
One of the more radical aspects of the face lift is to raise the ground floor by 3 blocks (~650mm) - I propose removing the concrete tiles (4400 tiles ~ 25 tonnes) & anchors on the wall plate and then jacking the timber roof up, removing the closing 12" block adding x3 rows of blocks and a new closing block. I understand I'll have to rise all my windows / doors & floors and re-slab my ceiling etc.
What is the best technique to jack up a roof ?
Acro props at the end of every second joist? internally or externally?
6th January 2010, 09:28 AM
This reply may not be terribly helpful, but I felt inexorably compulsed to say something to your request as this has to be one one of the strangest requests I've seen on this or any other building forum!
A return question would be - does it have to be done - is the building in danger of flooding, or why raise by 3 blocks, especially in a new house?
The other thing I would say, and it may not be that helpful either, is, can you not maybe just build into the roof - have you a cut roof or a prefabricated truss roof?
If it is a cut roof, then you may be able to re-convert the 3 feet required into the slope of the attic almost semi-dormer style without actually raising the roof, if you see what I mean. Although it does mean your attic gets tiny, and you would want to be sure the roof is well tied together to prevent spreading.
I have seen roof raising in London, a 2 storey house under a canopy of scaffolding, where the roof was stripped, and each and every rafter raised temporarily onto some support (can't remember what it was?) and then brickwork finished to the required level and about 2 weeks later the roof was let down again. But such a messy business is not lightly undertaken.
Also, you might require planning to raise your roof line/facade.
Would you be better off starting from scratch?
Best of luck with it!
6th January 2010, 03:14 PM
Thanks for the interest Gavin,
The main reason is flooding related - although never flooded - came within 9" of the ground floor level. I'm trying to explore all solutions.
Rising the floors which is the ultimate objective and moving upwards into the attic space would still leave my windows too low - and they would have to be moved upwards anyway.
The roof is a cut roof - left with lot of open space for future attic conversion. I had hoped to retain this space as is and convert it to additional living space while I'd have the plasters onsite.
It's more the lift of the unladen roof that I'm unsure of - and any suggestions are worth considering.
12th January 2010, 05:46 PM
I agree with Rogaire. This is a massive job and it should be avoided if possible. If the roof does have to go up, I would suggest taking it down completely, raising the walls and rebuilding the roof. It would probably work out less expensive and would be a lot less risky
13th January 2010, 09:11 AM
A draining ditch around the house ending in a sump with a submersible pump connected to a generator is propably the cheaper flood protection method.
21st January 2010, 05:16 AM
We wanted a double stored extension a couple of years ago...but we think that it wont be accepted by planning because of right of light. I don't really want to pay for someone to come and do the plans, then apply for it, only to be told no! this would cost thousands of pounds!
So the other option is to convert the attic into another bedroom...but to do this we would need to raise the roof. Then my friend suggested me you can get a company that does loft conversions and get a quote they would tell you whats possible also you need head room for the stairs they look at all of that small room.
Hometech are specialists in a range of Attic Conversions (http://www.techstore.ie/hometech/Attic-Conversions.html) Services
25th January 2010, 08:44 PM
You will not achieve the raising of a cut roof without major remedial works after. It will not be worth the effort! Much better to invest the money you were going to spend into a flood defense system. Something like what Heinbloed suggested may work, but sometimes in a flood situation there is nowhere to pump the water to. I do recall looking at an austrian demountable system which you can erect around your house before a flood (if anyone can find a link?). Remember that the flood defense system must also include protection against wastewater backing up into your property.
If your going advertise attic conversions why not do it openly and not the old "my friend suggested....." routine. Also did you even read the op. It is nothing to do with an attic conversion.
15th February 2010, 12:24 PM
Thanks to all who read this post - though it is not just an attic conversion.
Raising the floors / roof is only one aspect to the face lift. Other features proposed are adding front and back porches ~ 36m2. Sun room ~ 40m2. Changing all existing internal dry-lining from 37mm to 63mm. Stone cladding the entire exterior. Stairwell addition & attic conversion. Heating system re-position / consolidation.
Raising the floor isn't just about flooding risk - which is in train with the OPW etc.
I understand raising the roof will require a lot of remedial work - but with the face lift - this is a given. I did all the fixings originally in 2003 /elec /tiling /plumbing /2nd carpentry etc.
The house is H - shaped with hipped ends. The new porches will change the layout and involve taking down the middle roof and constructing a new roof parallel to the two sides - there will still be an inter-connector afterwards in the middle. While the middle roof is down I was going to raise the side roofs individually. Raising the roof / floor will give more height and the stone cladding a better presentation.
It is just a simple query on technique to raise two disconnected A-roofs (15m x 6m) without deconstruction. Tiles removed of course.
16th February 2010, 04:55 PM
...I have to query the cost benefit of raising your roof, vis-a-vis a new one.
A new, trussed roof would be cheaper than a cut roof in any case, and it would come c/w attic space therein. They are also very quick to fit.
There is also a H & S issue - you have to weigh up the practicality of trying to modify your walls, under a a jacked roof. It'd be a lot easier, take less time, and I would profer, be cheaper as a result. with roof removed completely.
The timber you do remove, you can still re-use and the remainder sell, btw, it's not as if you have to throw it away.
As for the jacking operation - acro's won't lift that securely or accurately - acro's are adjustable-length props - not jacks !
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