On The Tiles

With the rafters in place I covered them with OSB3 to stabilise and give added protection and strength to the structure.  The roof membrane was stapled on and battens nailed into place to give a 3.5" tile overlap.  I decided to use second-hand tiles; not because they are cheaper, because they aren't, but because they would fit in to the picture better.  I bought them from a guy in Dereham who had demolished a barn and had sufficient.  They're heavy things, tiles.  It took 2 trips with car and trailer to collect them.  As it happened he also had ridge tiles which are more expensive.

I bought 4 velux windows which came with the flashing and seals.  For these I had to cut out the spaces I had left in the rafters and fit the frames.  I hope I have used sufficient extra felt and sealant to ensure they are all watertight - but it wall remains to be seen.  I assume we will get plenty of rain between now and when I insulate and finish the ceiling, so I'm sure I will find out.

I have decided to go with 'wet soffits' - where the ends of the final line of tiles at the gable end are mounted on mortar which requires a fibre board underlayer. It means being much more accurate with the cut tiles and the spacing up to the first velux window.  There will be a fair amount of trimming needed to fit the tiles around the windows, but I'm sure it will all be worth it in the end.

The gulley is the next thing requiring finishing.  I have laid the board on supporting timbers to give a 2" fall over the length and painted it all with Flexacryl fibre-reinforced paint.  Martins Plastics told me that this stuff is good enough to line a gulley without fibreglass, lead or plastic and will stay waterproof and flexible forever.  However I am going to lay a fibreglass gulley once there is sufficient heat in the air - I need a good 10 degrees to enable it to cure and it has been frosty recently so I need to wait a while.


Meantime I built a hopper to take the water discharged by the valley and drain it to a downpipe.  It is a downspout from the old guttering, cut to length and encased in an OSB frame which is wrapped in fibreglass inside and out to prevent leaking.  I hope it works.



 

The Roof

The dream was to make the roof pretty much watertight before Christmas, but it just didn't happen. Too many school and social carol services etc. and wet evenings and weekends left me with bare rafters into the Christmas holiday.

So the noggins needed to be cut and fitted, the frames for the velux windows had to be made and squared and some additional bracing needed to be fitted at the ridge beam.  All of this meant multiple moves of the scaffolding.


Initially I had set it up right across the back of the extension so I could fit the soffitt overhang and fascia.  The new tower was split into two - part indoors and part out with the 4m boards lapped over three sections of scaffolding to make a long run.

Once that was complete I moved it to the drive to finish attaching the rafters to the wall plate using truss clips and angle brackets for the double rafters.  The noggins were all awkward because the gap between the rafters gave too little room either for the drill or for hammering in nails.  Once again every job took three jobs because of moving scaffolding and re-assembling it in the new position.

Once all the structural timber was up I went to Cushions for 11mm OSB3 boards to put on top. Wickes wanted £15 for each board, Cushions' were £9.80 so as I bought 15 I saved £78.  I spent 2 days fastening them to the rafters and taping the seams.  I made the box gulley out of off-cuts from the rafter ends - all cut at 20'.

It needed to slope 2" over the 4m run so it was a matter of lining up first and last, running a string between them and measuring at each rafter then trimming them with the table saw to fit.  It only took a morning and with the OSB cut and screwed down, with a little bit of silicone to seal the end - and a lot of yellow tape along all the edges, it should be water-tight enough until I get the membrane and battens.

I have left the holes for the velux windows covered with the OSB and will simply jigsaw them out when I am ready to fit them.  So now i may be able to get the floor dry enough to lay the final screed.  There are still some little bits of brick/block laying to finish off around the ends of the lintel, along the top of the driveway wall, the old back door and covering the steel post that supports the ridge beam.  I need to work out how many bricks/blocks I need and give a Saturday over to completing so I can do the last bits of insulation and fit the cavity closers.