Altering roof pitch

NickTellis

Hello all,

First time poster so be gentle.
We are looking to do an attic conversion and extension to a small 1960s bungalow in Galway by basically doubling the usable floor space. We had always planned on re-slating the roof as the old cement roof tiles are in poor shape, however, as it stands the roof pitch doesn't leave us with much head height (about 2.2 metres) with only about 3 metres usable floor down the middle.

Has anyone any experience with completely changing the pitch of a roof? We figure that if we're going to re-felt and re-slate it'd be the ideal time to bite the bullet and increase the pitch as well. Anyone have any idea of cost, potential problems, planning restrictions, etc? The house is about 8 metres wide by 13 long if that helps.

Any help or advice would be much appreciated.

sydthebeat

NickTellis wrote: »

Hello all,

First time poster so be gentle.
We are looking to do an attic conversion and extension to a small 1960s bungalow in Galway by basically doubling the usable floor space. We had always planned on re-slating the roof as the old cement roof tiles are in poor shape, however, as it stands the roof pitch doesn't leave us with much head height (about 2.2 metres) with only about 3 metres usable floor down the middle.

Has anyone any experience with completely changing the pitch of a roof? We figure that if we're going to re-felt and re-slate it'd be the ideal time to bite the bullet and increase the pitch as well. Anyone have any idea of cost, potential problems, planning restrictions, etc? The house is about 8 metres wide by 13 long if that helps.

Any help or advice would be much appreciated.

Firstly, planning is required if you change the roof pitch.

I would put a figure of approx €35,000 to hire a contractor to do this work. Thats based on an assumption of the roof costing 40% of a typical new build at e100 per sq ft, plus demolition and removal costs.

ircoha

What was done near me recently was that the roof was taken off and 600mm or so added to height of side walls and then the new roof put on at a lower pitch so as not to exceed the original height by much.

This needed planning but as u will need it anyway..

In your case, removing the rafters without damaging the ceiling could be a bit tricky, assuming the rafters are nailed to the ceiling joists.

Also when doing it I trust you will have the best insulated roof west of the shannon:)

NickTellis

Thanks for the replies folks. That's a very good point about damaging the ceilings and it's something I'll definitely be asking my architect/roofer about. I reckon with the extension, a porch and the removal of the old roof I could be looking at around 50,000 just for the roofing (ouch). I've also thought about perhaps extending the width of the new roof out over the eaves about 30 - 40 cms either side which along with the increase in pitch should give us that much sought after head height/floor space.

Anyway I've done up a rough design to bring to the architect to see what he thinks before we get him to do up the drawings for planning permission. Have a gander and let me know what you think - the light yellow is what we currently have and the darker yellow is what we hope to add. It's been many a year since I did mechanical drawing in secondary school so go easy.

muffler

I have just done a final inspection of a property here in Donegal that was reconstructed by increasing the roof pitch etc and included a balcony to the rear. The overall size of the original bungalow was about 18 x 9 metres and the contract price on that job was €75,000. That included basically everything except tiling and decor.

NickTellis

Over the last few weeks I've been looking at a house getting it's roof pitch altered by literally placing the new roof over the old one before the old roof is dismantled thereby keeping it watertight throughout the job so that presumably the occupants can remain in the house during the build. Anyone any experience with this kind of practice as it's something I'd be very interested in doing also?

NickTellis

Any roofers out there got any experience of constructing a new roof over an exisiting one? We're planning on changing the pitch of our standard bungalow gable roof and I was wondering if it's common practise/or possible to construct the new roof to the felt/membrane stage so that's it's water-tight before removing the old roof below?

The reason I'm asking is so that the house is never fully exposed to the elements and because ideally we'd like to live in the house during construction. As always any help or advice appreciated.

muffler

NickTellis wrote: »

Any roofers out there got any experience of constructing a new roof over an exisiting one? We're planning on changing the pitch of our standard bungalow gable roof and I was wondering if it's common practise/or possible to construct the new roof to the felt/membrane stage so that's it's water-tight before removing the old roof below?

The reason I'm asking is so that the house is never fully exposed to the elements and because ideally we'd like to live in the house during construction. As always any help or advice appreciated.

I have merged this thread with the other one you had on the same topic.

topcatcbr

NickTellis wrote: »

Any roofers out there got any experience of constructing a new roof over an exisiting one? We're planning on changing the pitch of our standard bungalow gable roof and I was wondering if it's common practise/or possible to construct the new roof to the felt/membrane stage so that's it's water-tight before removing the old roof below?

The reason I'm asking is so that the house is never fully exposed to the elements and because ideally we'd like to live in the house during construction. As always any help or advice appreciated.

I have seen it done so it is possible but i have never done it. It is a difficult one to estimate.

Id be inclined to do somthing along the lines of what ircoha suggested and raise the walls a little while your at it this will give substantially more usable space upstairs. It would depend on planning though.

NickTellis

Anyone know of a way to raise the walls and add a new roof while keeping the substructure water tight?

JohnBoy

Enclose it with a scaffold and roof that.

not gonna be watertight, but might work for a while.

budget to redo the ceilings as well.

with the best will in the world there's a good chance you'll have cracks in the ceilings.

budget for it, but dont tell your contractor. if lads know the ceilings are gonna be replaced they will destroy them. if they think they wont be replaced they might only crack a few rooms

if you know what I mean.

NickTellis

Does anyone have any experience with the Smartroof system? Is it a viable option if you're replacing an old roof on an existing house? How does the cost compare with doing it the "old fashioned" way?

Any thoughts appreciated...

muffler

Cheers nick.

metalscrubber

Hi NickT,

Re your post on the 4th July about building a new roof over an old one I watched this being done on an old cottage in North Meath.

I have photos of the process and the builders details at home (i think) - let me know if you want them and I'll PM them in the next day or two

Metal

NickTellis

Hey Metalscrubber, any chance of sending me on those pics? I'm convinced that constructing the new roof over the old one is the safest way to go, especially considering the recent weather we've been having. I've already sent you a PM but to no avail.

kforce

NickTellis wrote: »

Does anyone have any experience with the Smartroof system? Is it a viable option if you're replacing an old roof on an existing house? How does the cost compare with doing it the "old fashioned" way?

Any thoughts appreciated...

Have a SmartRoof on my own house. It's a good product in theory, allowing for full use of the attic space with good insulation values, although bad customer support let the product down. Expect to pay more than typical traditional roof construction.

NickTellis

kforce wrote: »

Have a SmartRoof on my own house. It's a good product in theory, allowing for full use of the attic space with good insulation values, although bad customer support let the product down. Expect to pay more than typical traditional roof construction.

What shape roof do you have? How much did it cost per square metre? Would you care to elaborate on some of those customer support problems?

muffler

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