The extension

Having received the post supports for the extension and wanting to start the extension roof prior to fitting slates on the gable ends I decided to tackle this next. This was not a major task. Two purlins needed to be cut to length and halving joints cut to locate the purlins on the frame. The holes in the tenons needed to be marked and then the frame dismantled and holes drilled - pegs needed to be made. The extension frame could then be reassembled and the post supports concreted into the ground.

Post Supports

Post support in position ready for concrete

Once the frame was pegged it was necessary to start to clad the gable end of the shed and cut rafters for the extension. I decided to use the same colour paint for the gable ends as I did for the ceiling and just had enough tongue and groove already painted to finish the one end. 

Cladding on the first gable end (the orange cord is attached to the cut off bottom of a plastic bucket that sits on the stove flashing to keep out the rain).

Once the tongue and groove was in place I cut and fitted 50 x 75 mm  treated softwood battens to take the oak weatherboarding. 

I had decided to use 100mm x 50mm treated softwood for the rafters on the extension.

The gable end with 50 x 75mm battens fitted and 100 x 50mm treated softwood rafters positioned but not fixed on the extension roof

The next job is to fit 25mm x 25mm battens inside the frame to fix the insulation to. I will use wastage from the shed rafters cut into 25mm widths for this. The frame will be covered with breather membrane prior to cladding with weatherboarding.

Finishing the roof

With some good weather allowing progress to be made the roof is now finished with ridge tiles in place and stove flue fitted. 

Detail of the lead flue flashing - partially fitted.

Finished roof

Starting to finish the roof

Before I update on progress of the roof I just wanted to mention the excellent service I received from Dean Forge. I waited six months for the posts (see post on 26.11.12.) I ordered from the original company and then gave up. I went to Dean Forge and they quoted the same price and I had them within five days! 

The roof
After much deliberation I decided to purchase some 12 mm thick tongue and groove softwood to form the ceiling. I purchased this from Southern Timber. I was unsure what the quality would be like but after applying knotting solution and four coats of paint the result was fine. I chose a dark red for the ceiling which I thought would suit the oak and also give a cosy feel to the interior. I painted the timber in strips of five pieces (which were 4.4 metres long). This took quite a while as I needed a total of 10 panels but the weather was poor so it was not a problem.

I waited for a forecast of dry weather for about a week (and this happened at the beginning of June) with the hope that the roof would be waterproof in this time. 

Getting the painted timber to the shed was not easy and eventually I took it through the house as this was the most direct route -  manoeuvring 4.4 metre long timber was not easy but I am pleased to say there where no breakages.

Getting the panels on to the roof was fairly straightforward and I nailed down with 65mm long galvanised nails.

A panel lifted on to the roof - painted side up to avoid damage

View of ceiling partially completed

Once the ceiling was fixed the next task was to fit counter battens to provide some air space for the insulation. I used double foil airtec insulation  (from Screwfix) as this is thin and should be sufficient for what I need. I zig zagged the insulation under and over the counter battens to provide some airspace - a compromise to avoid the roof becoming too thick.

The insulation fixed on the roof

View showing airspace

When the insulation was fixed I fitted Permavent breather membrane and fixed with battens.

Fitting membrane and battens

Once the battens were fitted the next task was to fit the fascia along the front and rear sides. I had purchased 150 x 25 mm air dried oak from Anton Coaker but this was not deep enough so I (reluctantly) set about cutting a tongue and groove to join the timber using a hand Lie Nielson Tongue and Groove plane. This was hard work as I had 8 metres of timber to join. Fitting on my own was not easy but clamping timber at the height required using  sash clamps did the job. I screwed the fascia to the rafters and will peg the holes over the screws.

End view showing the tongue and groove joint and support 

The front fascia fitted

Once both fascias were fitted work could begin to slate the roof. I plan to fit a wood burning stove so I contacted Dean Forge who advised me on the installation and arranged for a lead flashing to be made to go on the ridge of the roof and this was made in two days, meaning that slates could be cut as required without holding up work on the roof.

View from the west end with the slating partially completed. The stove will be fitted at this end and a temporary cover over the hole for the flue pipe can be seen 

Completion of the main frame

Just about 18 months since I laid the foundations for the shed the main frame is now complete. Making the most of a glorious spring day today I fitted the last two pegs holding the rafter to the wall post at the eaves. I tapped all of the pegs a bit further in and cut the pegs protruding on the outside of the building flush ready to begin cladding the roof and walls. I trimmed the pegs on the internal faces to about 12 mm. There is still some work to do on the little extension but I am still waiting for the post supports before I can conclude this part of the frame.

The last peg (just visible on the left of the image)

Looking up at the roof frame

Looking up at the roof frame

Looking west towards the shed

Fitting rafters

A number of factors significantly reduced the work I could do on the shed between the end of December and end of March - not least the weather. However the rafters are now cut and in place on the roof. I still need to cut the rear rafters to length and finishing pegging along the eaves but this should be completed fairly soon (assuming the weather is dry).

I have purchased oak feather-edge boards (from Yandles) to clad the back and sides and will be collecting slates on Wednesday (from Independent Slate Supplies). I need to order plywood, waterproof membrane, insulation and battens and work can progress on cladding the frame.

Oak feather-edged boards

The first rafters fitted

Rafters fitted and cut to length

Arrival of timber for rafters

At last the timber for the rafters arrived today. Finished moving and stacking by 4.45pm. A really great Christmas present.

The next step

All the purlins are now pegged but there are still a few pegs to make to fit to the main frame.

I have arranged for the lean to post supports to be made by Dean Forge. The posts will be galvanised and fitted in concrete - the oak post will be drilled at the base and sit on the plate and spigot - see drawing.