Home 
Planning the build
 
Why build an extension?
 
Initial design sketches
 
On-line Building Regs
 
Meeting planners
 Meeting building control
 Planning the foundations
 Planning the floor slab
 Marking out the footings
 Damp proof course issues
 Possible drainage problems?

 Construction of the walls
 Proposed roof structure
Windows diary
 Window challenges
 Initial window plans
 Making the casements
 Making the frame
 Designing leaded lights
 Making leaded lights
 Assembling the window
 The little window

 The door frame
Demolition diary
 The demolition starts!
 The demolition continues
 Still more demolition

Foundations diary
 Foundation issues
 Drain issues
 Digging the foundations
 Rethinking foundations!
 Pouring the foundations

Floor slab diary
 Rethinking the slab!
 Floor vent extensions
 Preparing the slab #1
 Preparing the slab #2
 Pouring the slab

Walls diary
 Preparing to build walls
 Build up to the DPC
 Build the walls #1
 Build the walls #2
 The gas men cometh
 Build the walls #3
 Finishing the walls
Roof diary
 Roof structure build
 Tiling the roof
 Finishing the roof
 Finishing the gables
 Roof insulation
 Guttering

Internals
 Floor screed
 Plumbing
 Electrics
 Shower room
 Shower room floors
 Shower room walls
 Utility room
 Utility room walls
 Utility room floor
 Finishing the windows

Project finished!
 Final inspection
 The certificate
 Final thoughts

 Twelve months on!
Out-takes!
 Mistakes
Costs
 Material costs
Links
 Links
Sister sites
 House re-roof project
 Home gas usage data

 Stop paint flaking
 DIY secondary glazing
 gare.co.uk

 


Making the wooden casement windows
 
 

The design of the window can be seen here.

Saturday, 3rd March: After picking up 6 metres of 70 x 50mm Redwood PAR (Planed All Round) wood, I cut it into the appropriate lengths for the three casement windows - six uprights and six shorter horizontal pieces. Incidentally, the actual size of the wood when it is planed is 44 x 69mm.

I bought long lengths of timber to cut pieces with as few  knots in the selected lengths as possible. In the past I built windows out of hardwood but this can be very expensive nowadays and to be honest hardwood is not really required when the windows are going to be painted.
Then came the task of carefully marking out the mortise and tenon or bridle joints on all four sides ready to be cut out using a band saw.

I use a pencil rather than a knife to do this marking so that the marks can be sanded away upon completion. I always mark the areas I need to cut away to make sure I don't make any mistakes.
A wooden guide was clamped to the band saw top to ensure that every cut was the same. I have to say that using a band saw is probably not the most accurate way of cutting the joints, but is quite quick! Mind you, after tightening the blade the problem did disappear!

Be careful about which pieces you cut the outside (short pieces) and the inside (long pieces) - it's so easy to make a mistake if you are not paying attention.

On the upright pieces, I used a coping saw to cut out the mortise slots.


I then used a chisel to square off the the bottom of the mortise slots.


Here are all the completed components of the three casement windows. The next step is to glue them together.


Here is the first window being glued together using four sash cramps to pull everything together. You have to make sure everything is square at this stage in the proceedings!


After planning the extraneous wood off the joints, all that needs to be done is to sand them.

Mistake #1: Well, I did say I would say when I make a mistake so here goes with my first one. I had to remake the first casement I made because the surface I used to glue it together on was not quite flat. This resulted in the frame being a little twisted which is just not acceptable!

 

 


Using a flat-bed sander to finish off the frame joints after filling a few 'holes' with neutral coloured wood filler.

 

 


Monday 5th March: Two of the frames following the initial sanding of the corner joints.

These do look deep compared to an old widow that only contains a single piece of glass but these need to accommodate a 22mm double glazed unit plus a real leaded light window making it effectively triple glazed.
Here are thre window frames after sanding.

 


The next task to hand was to route the plain chamfer on the inside of the window frame. These went up to 50mm away from the corners.

 

 

 


This picture shows the chamfers. I've not decided whether I will leave the end of them curved or whether I should flatten them with a chisel.

 


Using 12mm x 12mm softwood, I created a 12mm by 12mm rebate to fit the leaded light panels - the corners were mitred as can be seen in the picture. The softwood strip will be pinned and screwed to the fame.

In other windows I have built I routed out this slot, but because I also have to fit the 22mm double glazing unit behind the lead light panel, it seemed easier to just add the strip.
The windows sanded and ready for the leaded light panels to be inserted once I have made them!

 

 

 

 

 


I routed a small channel near to the OUTSIDE edge of all four sides of the three casement windows.

This is to prevent water getting trapped between the casement and the frame.


 

One of the three completed casements

All the frames have now been primed with aluminium primer paint.
I will need to chamfer the opening side of the casement otherwise it will jam against the frame. The width of the windows are 450mm so the diagonal will need to be 450mm also. The next job will be to build the window frame itself.

Back to home