Making a silk purse from a pigs ear - Lean to

[avsoftware4u]

Hi guys and thank you for this amazing forum of help and inspiration, I am hoping a few great night have some ideas on best practice for my solution.

So we inherited the rather thrown together lean to (pictured).

As we simply cannot afford to and don't own the house to justify spending to have it replaced, I wanted to try and fix it up for my wife.

Sadly she was recently diagnosed with brain cancer and loves the garden, so I'm going to do my best in the cheap, beg borrow and ok, not steal but do my best to make it a nice recovery area for her while having treatment.

Anyway enough of the sob story, we have a project to get my head around.

So the roof is tragic and as you might see, the patio doors are smashed (replacement French doors pictured)

So the new doors are excellent quality and reinforced internally.

You might notice that the "wooden lintel?" Is twisted, so that's got to go anyway.

Can the rafters sit directly on the frame of the new French doors?

I guess that depends on what I intend to do with the roof, so going back quickly to the French doors I got them from Facebook cheap and while the width is bang on identical to the old patio doors, the height is around 150mm taller, meaning my roof will sound half the angle of slope, but there will be some drop off. Height difference after new doors of around 150mm

The old Window on the right might have to stay unless I can find a cheap one on Facebook by luck, I will have to lay I think a course of bricks or 2 above that window to equal the height of the new doors

From research this means I'm going to have to deck the roof with something like 18mm osb3, ply etc. No problems.

However if I do have to install a lintel then that will most likely lose the majority of the slope, I'm estimating I have around 150mm above the French doors before the roof will be almost level.

Ok on to roof type.


Options so far are, corrugated bitumen panels or felt, but I'm guessing that felt would be heavy if not needed to have to walk on to fit?

Any other ideas I'm all ears and a nice thank you in advance for any help offered

 

[footprints]

Looks like a project! I guess you may have to beef up the rafters depending on what the roofing maker advises, best suggestion I can make is insulated metal roofing like this.

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A bit of guttering would not go amiss either.

Certainly need some kind of lintel above the door but I suspect a bit of the same size as the current will do as we are pretending that there is no such thing as building regs !!

 

[Mr Chibs]

Blimey

What's the 'room' going to be used for? i.e. used daily/once in blue moon.

Presume the brickwork is single skin thick?

 

[avsoftware4u]

Looks like a project! I guess you may have to beef up the rafters depending on what the roofing maker advises, best suggestion I can make is insulated metal roofing like this.

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Elevate your projects with top-quality insulated panels from Colour Clad. Enjoy energy efficiency, easy installation, and nationwide delivery within 3-5 days. Explore our range today!

www.colourcladprofiles.com

A bit of guttering would not go amiss either.

Certainly need some kind of lintel above the door but I suspect a bit of the same size as the current will do as we are pretending that there is no such thing as building regs !!

Thanks, yes I do intend to put guttering, what part of building regs are we " pretending", lol to ignore, I mean it's already here, I'm just trying to make it more structurally sound?

 

[avsoftware4u]

Blimey

What's the 'room' going to be used for? i.e. used daily/once in blue moon.

Presume the brickwork is single skin thick?

Cheers Mr Chibs It's like a summer room really, so she can relax and nap out here in the day, watch TV etc after her treatment. We spend a lot of time out here already lol.

Yes small single skin wall on the right under the window and the left hand return, which also has a couple of those old metal Windows like the front

 

[footprints]

Just that I the whole thing would never meet any building regs for a habitable room, but as a lean to we won't be worrying about that. Just covering my suggestion as there is usually someone eager to shout OMG and to quote chapter and verse on building standards!

 

[Harry Bloomfield]

Looks like a project! I guess you may have to beef up the rafters depending on what the roofing maker advises, best suggestion I can make is insulated metal roofing like this.

I agree with the insulated metal for the roof, but the rafters if they remain as is, will need timbers at right angles between them, to properly support the metal roof and for the roof to be fixed down to. It looks like the existing corrugated plastic, is just draped across the rafters, and dips down in the gaps between - because they have no support. You could always then add extra insulation and plasterboard maybe at a later date if needed.

The metal box section is fixed down with special screws, via the bottom of the channel, unlike other corrugated roof coverings. Every second or third bottom of the channel is screwed down. With timbers across the width, every metre or so.

 

[Alastairreid]

Not advisable to rest the roof on the head of the doors, even if there's not much weight in the roof itself you still have snow loadings to factor in.
I would put a flat roof on with an epdm covering..consider insulating between the rafters as it will be freezing in winter.

 

[avsoftware4u]

Just that I the whole thing would never meet any building regs for a habitable room, but as a lean to we won't be worrying about that. Just covering my suggestion as there is usually someone eager to shout OMG and to quote chapter and verse on building standards!

Got ya, no definitely not habitable, cheers

 

[avsoftware4u]

I agree with the insulated metal for the roof, but the rafters if they remain as is, will need timbers at right angles between them, to properly support the metal roof and for the roof to be fixed down to. It looks like the existing corrugated plastic, is just draped across the rafters, and dips down in the gaps between - because they have no support. You could always then add extra insulation and plasterboard maybe at a later date if needed.

The metal box section is fixed down with special screws, via the bottom of the channel, unlike other corrugated roof coverings. Every second or third bottom of the channel is screwed down. With timbers across the width, every metre or so.

Sounds expensive though when I am trying to do it on the cheap?

 

[avsoftware4u]

Not advisable to rest the roof on the head of the doors, even if there's not much weight in the roof itself you still have snow loadings to factor in.
I would put a flat roof on with an epdm covering..consider insulating between the rafters as it will be freezing in winter.

I did consider Firestone EPDM on the deck, but also want sure if that would be more expensive, pretty sure it will be more than felt, and maybe more than the corrugated, will have to check pricing on it

 

[Harry Bloomfield]

Sounds expensive though when I am trying to do it on the cheap?

Measure the length and span, work out how many panels you might need, then price then up. From memory they come in 2, 3 and 4m lengths, so obviously if that would fit without cutting, you save. It also comes in two thicknesses of steel, with the thinner able to buckle a little under your weight if you walk on it, but it is cheaper. I did my 24 x 12 foot garage with it and my add on 16 x 12 workshop at the back.

 

[avsoftware4u]

Measure the length and span, work out how many panels you might need, then price then up. From memory they come in 2, 3 and 4m lengths, so obviously if that would fit without cutting, you save. It also comes in two thicknesses of steel, with the thinner able to buckle a little under your weight if you walk on it, but it is cheaper. I did my 24 x 12 foot garage with it and my add on 16 x 12 workshop at the back.

So you mean you don't use a deck for these panels? Because of the angle I thought it had to have a deck

 

[Harry Bloomfield]

So you mean you don't use a deck for these panels? Because of the angle I thought it had to have a deck

No need for a deck, just bare timber joists to fix to and support the panels. As said, you will need joists across from side to side and I would suggest at around 3' intervals. The steel is galvanised, then colour painted both sides. It comes in at least three colours brown, pale green and grey. The manufacturers say they last a minimum of 10 years, mine is 15 and no sign of any degradation at all, not even any rust on a corner I cut. They suggest if cut with tin snips, the galv is able to protect the cut edges - they would seem to be correct on this point.

As said, measure it and price it and the timber up. You might be able to save on the timber cost, buying reclaimed timber. You can even buy ready made plastic profile, for draft sealing the box shaped ends, against a flat surface.

One downside is that it can be quite noisy under it, in heavy rain. Me, I love that noise

 

[avsoftware4u]

No need for a deck, just bare timber joists to fix to and support the panels. As said, you will need joists across from side to side and I would suggest at around 3' intervals. The steel is galvanised, then colour painted both sides. It comes in at least three colours brown, pale green and grey. The manufacturers say they last a minimum of 10 years, mine is 15 and no sign of any degradation at all, not even any rust on a corner I cut. They suggest if cut with tin snips, the galv is able to protect the cut edges - they would seem to be correct on this point.

As said, measure it and price it and the timber up. You might be able to save on the timber cost, buying reclaimed timber. You can even buy ready made plastic profile, for draft sealing the box shaped ends, against a flat surface.

One downside is that it can be quite noisy under it, in heavy rain. Me, I love that noise

Ok well that would certainly reduce cost by not having to use a deck, do you think I could get away with resting the rafters panels directly on top of the French doors with these panels or are they were heavy? Or do you still think a 100mm ish wooden lintel is necessary, I mean the only weight it will ever really support is the roof itself and and snow or heavy rain???

*Edit*

Did some research so I understand more, bit which thickness do you think I can get away with? Do you mind me asking where you bought yours and what thickness you chose?