Lean to shed roof
Discussion
The correct thing to do would be to grind out some of the mortar between 2 brick courses, insert lead, repoint, then dress down the face of the building and into the felt roof. Anything else risks water getting between your felt and the wall, and rotting the ridge beam.
Having said that, there probably thousands upon thousands such lean-tos with just some mastic/sealant running along the top edge.
Having said that, there probably thousands upon thousands such lean-tos with just some mastic/sealant running along the top edge.
fooman said:
Don't use felt, get a single sheet of edpm, Firestone is a good brand.
Yup. Unless you specifically want the aesthetic of felt then these days edpm is usually a better solution. Re making good against the wall of the house I would assume it would be best to run the material up the wall and then grind out the mortar and fit and fold lead flashing. There are also those tin flashing kits for edpm to consider.
Baldchap said:
My worry with this design is what happens on a mega windy day...
As above, if it's enclosed lift becomes less of an issue.Build it strong, which means using joists of an appropriate size rather than 2x4, glue and screw the OSB roofing and proper footings mean it won't go anywhere.
The bigger concern when I built one was loads transferred to the wall. I extended the ledger board so I could use longer fixings (resin anchors) and go through into the pilaster, so at least tieing it in to the strongest part of the wall.
Regarding the flashing. As stated above the correct way is to cut the mortar and embed the flashing and make good. For a lean to it is quite common to use aluminium or GRP profiles which are sealed to the wall with sealant. A good quality silicon will do the job of keeping water where you want it, and the choice of colours means it should be inconspicuous. Just running a fat bead along the roof/wall joint isn't the way to do.
PhilboSE said:
The correct thing to do would be to grind out some of the mortar between 2 brick courses, insert lead, repoint, then dress down the face of the building and into the felt roof. Anything else risks water getting between your felt and the wall, and rotting the ridge beam.
Having said that, there probably thousands upon thousands such lean-tos with just some mastic/sealant running along the top edge.
Very true.Having said that, there probably thousands upon thousands such lean-tos with just some mastic/sealant running along the top edge.
What you can get away with depends on how exposed to rain it is, the porosity of the brick etc, and how much it matters if a small amount of moisture comes through.
It might pay to bear in mind how things will look if the shed is ever removed?
I built something nearly identical to that quite a few years ago in a very exposed place in the Penines. I did the roof in 2 layers of bitumen felt from screwfix, not the cheap shed felt. You have a nailed base layer of a lighter felt, then heavier stuff on top. all stuck down with lashings of bitumen adhesive stuff out of big cans. It's a messy tough job, but looks good when it's done, no wrinkles. It's a while since I did it, but I just followed the manufacturer's instructions to the letter and did some googling on the best way to do the edges and corners. It's still good now.
The only thing I cocked up was the flashing. Because my house is render over block there wasn't a convenient course to lay proper flashing into, so I used Flashband. It never looked great, it did last about 5 years, but now it sometimes weeps water in driving rain. Need to re-do it.
I was a quite worried about wind lift because of the location so I put a concrete footing under each leg, about a foot square and dug down about 2ft. Used post feet and anchor bolts the secure the leg to the footing, plus it keeps the wood up off the wet ground. It's never shown any sign of moving.
The only thing I cocked up was the flashing. Because my house is render over block there wasn't a convenient course to lay proper flashing into, so I used Flashband. It never looked great, it did last about 5 years, but now it sometimes weeps water in driving rain. Need to re-do it.
I was a quite worried about wind lift because of the location so I put a concrete footing under each leg, about a foot square and dug down about 2ft. Used post feet and anchor bolts the secure the leg to the footing, plus it keeps the wood up off the wet ground. It's never shown any sign of moving.
fooman said:
Don't use felt, get a single sheet of edpm, Firestone is a good brand.
Agreed, I recently extended my workshop with a 21' x 8' lean-to and fitted a 'rubber' roof, supposed to last 40 yrs + (which will see me out), no issues so far.My neighbour got a new shed a few months ago and the felt blew off the top in the recent storms.
I've seen EPDM, felt and GRP roofs go wrong.
It's more about doing it right, using quality materials you understand, than any one thing being necessarily the 'go to' answer.
Depending on the location, I'd be considering either some solar panels or roof lights.
Rubber roof is better with fewer edges and other 'details' I think?
It's more about doing it right, using quality materials you understand, than any one thing being necessarily the 'go to' answer.
Depending on the location, I'd be considering either some solar panels or roof lights.
Rubber roof is better with fewer edges and other 'details' I think?
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