Mike's ext'n & renovation (solar panels)

[the bear]

Hi Mike, quick question regarding the eaves carrier, whats it actually made of and does it breath?
Thanks
Mark

 

[kostello]

It looks like slater's felt..... Some people use wide dpc... There is a black PVC product called felt tray that does the same job

 

[Mike G]

Hi Mike, quick question regarding the eaves carrier, whats it actually made of and does it breath?
Thanks
Mark

I've used underslate felt, as Kostello said, simply because I had quite a lot left over from doing the temporary flat roof. It doesn't breath, but it doesn't have to, as it is all on the outside of the line of the walls. In other words, it is just over the eaves, not above the room below.

 

[the bear]

Thanks for the answer
Mark

 

[Mike G]

Annoyingly, I have lost a whole load of photos. I even had one of a bright glowing object in the sky which I was going to ask you guys about.

I carried on working on the Utility roof. I had to make some little ledges in the corner of the returns either side of the roof (the wall is set back) to take the lead which will form a little back-gutter, preventing water gathering against the return. The difficulty on the "old" side of the roof is that the old building will increase in size by about 120 to 125mm to each wall face, and, furthermore, I couldn't attach anything to the rotten corner post so that I could remove it at a later stage to replace.



You can see what I am talking about here, underneath the elbow in the temporary down-pipe, clad in blue breather-membrane:



I finished the felt and battens both sides. I also offered a few tile samples up to get an idea of what things would look like:



A complete change of scene. I moved to the south gable, and before I could build the end of the infill wall, I had to fix the bracket in place which attached the end of the longitudinal beam to the glulam beams. Well, the former had a twist in it. To take this out, I put one of the 6" coach screws in the top to locate one corner, then nailed a block to the bottom to use as a whacker to untwist the beam. Remember that this is a really chunky item made up of 3 big pieces of 200 x 50 fastened together, so taking out a twist isn't easy. Anyway, a trick is to put a nail in at 45 degrees, and then hammer it home. You can see from the mark how much movement I got:



I bolted that all up, but again, no photos. It wasn't a straightforward exercise, as I had to drill in to the glulams from different directions to meet in the middle, then bang a piece of threaded rod through the combined holes.... Any, no photos, you'll just have to take my word for it.

I then built the little studwork wall, set back from the line of the gable. I could only build it to cill height because the temporary roof was in the way. I also removed the old lime render below a line just above the roofline:



Just to reiterate that this is a slate roof (25 degree pitch), and thus orthodox exposed rafter feet, rather than sprockets (slate has to have a flat line, with no kick):



Three new rafters in place:



I worked out the gauge for the slates, did the eaves carrier as before (again, a photo has gone missing), and started felting. Unfortunately:



Not enough felt. So I did a little infilling job before it went dark, putting in some upstand timbers to support the lead flashing at the junction of roof to wall:



Off to the Builders Merchants to discover that they have run out of membrane, so a quick change of plan for tomorrow is in order. This is a pity, as it might snow on Thursday, and I really don't want to be on the roof again whilst it is snowing, and I don't want the extension filled up with snow if I can help it.

 

[the bear]

Hi Mike
First, apologies for more questions about your roof, hope you don't mind. Firstly I find this stuff really interesting and like to understand the reasons behind stuff and what the options are. The second reason is I'm hoping to redo the roof of my garage in the future and would like to get a similar look to what you are achieving (sprockets and plain tiles)
With regard to the 25 degree slate roof, did you consider interlocking double plain clay tiles? I understand they can be installed down to lower angles than normal and would match the rest of the roof?

Mark

 

[Mike G]

Hi Mark.

I certainly don't mind questions at all. That's why I post.

No, my palate for this project, being a vernacular restoration, is traditional local materials: clay plain tiles, clay pan tiles, thatch, and slates. Pan tiles are traditionally used on outbuildings, and this property has never been thatched, and has too shallow a pitch anyway. So, clay plain tiles and slates is my choice. I'm not a big fan of slate, but I had to have a low roof to get under the bedroom window (which had to be big enough to be the escape window for the room), so I had little choice but slate. Interlocking tiles of any description just aren't traditional.

 

[Mike G]

I spent rather a lot of time finishing off the sprockets, and particularly making the boards that slip in between them to close the eaves. These were all re-sawn from seasoned oak on the bandsaw, then planed, bottom edge shaped, sliced to the right height, and, after the sprockets had been fixed, individually measured and cross-cut to length. Anyway, here is a barrow full of sprockets, and wedges. I didn't make the entire length of sprocket out of oak as that would be very wasteful of wood, so I cut some wedges out of scrap rafter off-cuts:



Here they are all screwed in place:



I then pushed the oak infill boards into place, after having cut them to length, and applied a bead of expanding spray foam to the junction at the bottom to secure them, and to prevent any insects finding even the tiniest of crevasses:



Looks a nice day, doesn't it? Sprockets showing up nicely against the sky:



I started nailing the wedges in place, but realised I had cocked them up, so made some more. Here is the jig, adjusted to account for the error:





Wedges in place:



The a strip of underslate felt as an eaves carrier again, as before:



Then finally I could start the last bit of felt and battens on this roof. This little bit of hail didn't stop me:



But the snow did:





So I headed off to the builders merchant to get some flooring and bits and pieces, pretty confident that I won't be on the roof tomorrow.

 

[StevieB]

Mike - looking good as always. You may have said it but I cannot find a mention in the thread, so can you tell me why you use sprockets rather than cutting a birds-mouth in a rafter and overhanging that? Aesthetics, tradition, pitch of the roof or some more functional reason? I realise the sprockets will allow the edge of the roof to 'kick out' - does that have a practical purpose?

Cheers,

Steve

 

[Rod]

Slows the run off or shoots it away from the walls?
Interesting question.

Rod

 

[Wizard9999]

Mike - looking good as always. You may have said it but I cannot find a mention in the thread, so can you tell me why you use sprockets rather than cutting a birds-mouth in a rafter and overhanging that? Aesthetics, tradition, pitch of the roof or some more functional reason? I realise the sprockets will allow the edge of the roof to 'kick out' - does that have a practical purpose?

Cheers,

Steve

Presumably because he wants the exposed (visible) sprockets to be in oak, but doesn't want to use oak for the rafters that will be hidden in the roof?

Terry.

 

[TrimTheKing]

Mike - looking good as always. You may have said it but I cannot find a mention in the thread, so can you tell me why you use sprockets rather than cutting a birds-mouth in a rafter and overhanging that? Aesthetics, tradition, pitch of the roof or some more functional reason? I realise the sprockets will allow the edge of the roof to 'kick out' - does that have a practical purpose?

Cheers,

Steve

I think it's purely an aesthetic thing, to give some visual interest to the roof, but Mike will be able to confirm or correct.

Cheers
Mark

 

[RogerS]

All explained here...http://www.roofconsult.co.uk/articles/tiling/tips91.htm A very detailed website on all things roofing.

 

[the bear]

Mike
You say the sprockets are seasoned wood, is that air or kiln dried? I built a cover for my outdoor pond filter in the last house out of a mixture of both as it was what was to hand. The kiln dried stuff didn't move and the air dried stuff did, which was the opposite of what I was expecting (I definitely didn't mix them up). Are you expecting much movement in the sprockets. Not a concern for the sprockets them selves but I wonder how well the eaves closer boards will therefore hold up given the effort you have gone to rebating them into the sprockets etc. (Looks great by the way)

Mark

 

[RogerS]

Mark, it depends on relative moisture levels in the wood.

Air dried is what exactly? Unless an individual piece has been measured then the moisture level in air-dried could be further away from ambient than kiln dried was the other way, if you follow which would explain the movement.

 

[the bear]

Yes Roger I understand that. To be honest I expected both to move to some extent and the design allowed for that. I was surprised the kiln dried didn't. When I used the same batch of Kiln dried in the house it didn't move there either, though it was acclimatised in the house prior to final milling.

I'm not aware Mike has measured relative moisture so was just wondering what he had used (air vs Kiln, albeit a relative comparison) and expected to happen and whether the eave closure boards would hold up. I'm not really doubting they will, he is clearly very knowledgable. I'm likely to steel his methods on a garage re-roof so am interested to know why he has approached stuff as he has.

Mark

 

[Mike G]

All the answers given for sprockets are basically correct. It is tradition and aesthetics (a roof looks so much better with a kick at the bottom in my view), and it is done in oak because all cottage rooves around here were done in oak (or chestnut).

They are a mixture of seasoned oak and green oak. I don't expect a lot of shrinkage from green oak outdoors, but there will certainly be some, however it shouldn't make much difference to anything. The eaves closers might get looser in their grooves, but the grooves are deep enough that they'll never fall out. The reason for the mixture is no more than the pragmatic: I had a whole lot of scrappy bits of left over oak, which has seasoned in an ad hoc manner in my woodstore over the last few years. Unfortunately, I didn't have enough to do all the sprockets, and those on the old cottage, when it comes to doing the front roof, will all be in green oak. In fact, I've ordered the timber for those already.

Disappointingly, my oak doesn't arrive until next Friday, so I have another week of just doing bits-and-pieces jobs.

Nice link, Roger. Thanks.

 

[Alex]

Love this build thread. I think having heavy masonry on inside and stick frame on the outside must be ultimate way to build.

Loving roof sprockets. I've done them before for customer where we use tongue and groove match board over roof joists as felt support and so You didn't view felt from ground. The pre routered out bits to take eaves closure boards are genius. Are you venting the loft space? I ask as I've fitted that breathable roof membrane on a few jobs and had to go back and fit vent tiles and soffit vents.

 

[Mike G]

I considered T&G, but ultimately took the view that a grey roof overhang 15 feet up in the air would be pretty unobtrusive. I've done T&G before for clients when I've specified a larger overhang, though (mine is only about 240mm.

Vent's? Not sure yet. The tiles I have in mind, being handmade, have the traditional double camber, which means lots of gaps, and lots of airflow. I've not had a problem with that before. The insulation follows the rafter line, so there is no loft to vent, generally, although there is a small area over the 4th bedroom. I don't like unvented voids, so I'll either leave a terminal from the mechanical ventilation system up there, or I'll but a couple of vents into the room below, where the mechanical ventilation system will pull the air through anyway.

 

[9fingers]

Apart from good roof ventilation, I reckon a vapour barrier on the warm side of the insulation is key.

I radically extended my bungalow by building another floor on top and adding to both ends.
It has a cold loft as was the trend in 1985 and even on the dampest time of year, the underside of the roofing felt is always bone dry. The building inspector was impressed at the time when flashing a torch round in the roof, he saw no glistening on the felt. It has remained like that year after year. It is only a layer of polythene above the plaster board, cost next to nothing but really effective.

Bob

 

[Mike G]

Absolutely, Bob, although in tests apparently foil-backed plasterboard performs just as well. I did my first 2 or 3 houses using polythene, but tend to use foil backed plasterboard these days just out of simplicity.

 

[9fingers]

I think yours will be a warm roof(?) so are you using foil plasterboard on the under side of the rafters or some other sort of vapour barrier?

Bob

 

[Mike G]

No, mine will be a cold roof. There will be insulation between and under the rafters, with foil backed plasterboard inside that.

 

[9fingers]

Maybe I have my terminology wrong It sounds like your loft will be warm then? (unlike mine)

Bob

 

[Mike G]

Yes, it will Bob. Cold roof, but warm loft.

 

[billybuntus]

Maybe I have my terminology wrong It sounds like your loft will be warm then? (unlike mine)

Bob

A warm roof is generally placed over the rafters on the outside. A flat roof for example would have kingspan laid externally and fixed in position with long fixings into the structure beneath. You've then board over and put your chosen roofing material on.

A cold roof is insulated at ceiling level. The difference is that there are no cold spots with the warm roof method. No thermal bridging etc

 

[Mike G]

The weather just hasn't been co-operating:



So I bought some 22mm t&g moisture resistant chipboard flooring, pinged a line , and got on with it:



A chipboard floor done badly can be awful. Squeaky, bouncy, liable to collapse...... But with a bit of care, they can be perfectly alright. We are having carpets in the 2 new bedrooms, so chipboard is perfectly OK. However, I glued all the boards to all the joists, using a flexible gap-filling adhesive, and I glued all the T&G joints together using copious amounts of PVA glue. I also nailed the boards quickly into place with the nail gun, and ring shank nails, to make sure they were well bedded into the adhesive before that started going off. I then went back and put 4 big screws (60 x 5.0) across ever board at every joist. If that bugger ever squeaks I'll eat my hat. Anyway, dull stuff, but here are some photos:







I also spent a little time in a kitchen showroom with my wife, trying to make some decisions. I'll make the kitchen, but what worktop, what sink, and particularly, what sort of oven (range cooker or wall-mounted double oven) are still up for grabs. We're no further forward.

 

[AndyP]

I am surprised that the silly soft stuff keeps you indoors

Why anyone chooses to bend, kneel or squat to take things in and out of an oven is beyond me. Wall mounted double oven anytime. For some inexplicable reason as rare as hen's teeth over here, in the sub €1000 price range.

 

[Alex]

Vapour shield before plasterboard seems good way for you to go. Just use coated drywall screws on ceilings as the black ones rust, had that on a job once.
Don't know about glueing p5 board onto joists. What happens when you need to lift for maintance?
I usaully glue t & g and screw boards down. Leave expansion gap round edges. Never had a squeak, touch wood.

 

[Mike G]

It's a low modulus gunk, Alex. It isn't like it would break the boards if you removed them. Frankly, I'm not sure how you would get boards up anyway. I've always just cut a hole, then nogged-out and screwed a new piece of chipboard in place. For a really fancy job, you could rout out with a tapered cutter, and use the same cutter to make the new insert.

 

[Alex]

Low modulus? Silicone .
True, true for spot repairs to cable or pipe but for re install could spell problems. Just this last year i replaced two chipboard floors after plumbers and electricians it would have been an absolute nightmare if they'ed been glued down.

 

[chippy1970]

I wouldn't have nailed the floor down I've always screwed it down. Hopefully the gluing down will help stop any squeaks but I wouldn't count on it.

 

[chataigner]

I am surprised that the silly soft stuff keeps you indoors

Why anyone chooses to bend, kneel or squat to take things in and out of an oven is beyond me. Wall mounted double oven anytime. For some inexplicable reason as rare as hen's teeth over here, in the sub €1000 price range.

:text-+1:

As for the floor, I agree about cutting holes for access - getting t&g up without damage is just too difficult. It's no big deal to add a noggin or two to support the patch as Mike says. That's how I've always done it anyway.

 

[9fingers]

I'll throw this is as an idea.

When I laid the floors in my place back in 1984, I marked the floor near the skirting with the location of all the wall studs. I had forgotten all about this minor act of wisdom until recently when converting a room to a new purpose, I had the carpets up, noticed the marks and they made it very easy to cover a wall with spur bracketing for shelves.

You might want to get the marker pen out Mike?

Cheers
Bob

 

[Alex]

Nice idea Bob, but you don't need no fancy gizmo's,hidden markings or wall wispering (knock-knock) Just use a rare earth magnet to find fixing screws or clout nails. Hold a magnet loose in fingers while dragging across a wall, soon as you get a grab mark it then move vertical to see if there's further grabs which makes it a stud.Works with lathe and plaster walls as well. Just not woven ones.

 

[9fingers]

Nice idea Bob, but you don't need no fancy gizmo's,hidden markings or wall wispering (knock-knock) Just use a rare earth magnet to find fixing screws or clout nails. Hold a magnet loose in fingers while dragging across a wall, soon as you get a grab mark it then move vertical to see if there's further grabs which makes it a stud.Works with lathe and plaster walls as well. Just not woven ones.

True - there are all sorts of stud finding techniques but this one is a dead cert, assuming they were fitted plumb in the first place!

Also rare earth magnets were ever rarer in the 80s when I did it :lol:

Bob

 

[Mike G]

I do tend to do that Bob, but don't forget my external walls will be blockwork (inner skin) so this only applies to internal walls.

 

[kostello]

He won't need to mark the stud positions...... It will all be in the cad designs.....

In 20 years he can just get the measurements off the computer.....

 

[Mike G]

. Yep, pretty much.

There's also about 3 million photos recording the positions of everything.

 

[9fingers]

I do tend to do that Bob, but don't forget my external walls will be blockwork (inner skin) so this only applies to internal walls.

True! I must try and keep focussed on your inside out house technique Mike :lol:

Bob