Case Study 

Garden Room with Veranda

1 - Our Mission

To replace this tumbledown relic with a garden room that could be used for storage and leisure.


First – clear the site.

4 - Level the frame

This shows the mid side of the frame after the frame had been levelled.  This was done by taking one corner (in this case the front left corner) as the datum and levelling away to ensure the frame is perfectly level all round.  THIS IS IMPORTANT!


We used Postcrete to secure the foundation timbers in the ground, first placing a brick at the bottom of the foundation hole on which to rest the foundation timbers.

7 - Fit The Floor

Set the floor joists at 400 mm centres.  To ensure that the floor does not “bounce”.

The blue tarpaulin was covering the wood materials as I was having temperatures of 32C when the rest of the UK was 24 -28C!

Notch the joists to allow an upstand of 40mm.  This allows the flooring to run over the Joint “ears” where the mortise panels slot into the top and bottom panels of the joints.

The JK150 panels used here are 18mm thick and the “ears” are 20mm high, leaving a 2mm tolerance.

The same technique (in reverse!) is used for the ceiling joists if used.

10 - Add The Doors

Not the pop group. (although Back door man album could be appropriate!)

Once the cladding is complete the final act is to fit the delicate items, in this case the glazed doors.  The right hand door is fixed, and the other two open.

2 - Make up the Joints

Becky and baby showing how easy it is to make up the joints. 

All 8 corner joints and the 4 extension joints were assembled by Becky in less than 10 minutes. 

Despite never seeing the JointKit product before!

5 - Assemble the top frame

First we fitted the vertical posts to the bottom frame.

Then we fitted the centre beam to the top of the vertical beams.

Next the short front side beams and the front corners were added to the front vertical posts. 

Finally, the front horizontal beam was added to the top corner joints.

Note the rear side beams and rear corners resting on the rear of the bottom frame awaiting assembly in the same sequence as the front upper frame.

8 - Add the studs

Vertical stud timbers are used to provide support for internal and in this case external cladding.  Set at 300mm centres, we used Oriented Strand Board (OSB) as an interim cladding for insulation purposes.  For a top class finish the studs would be covered internally by plasterboard.

Insulation can be added both between the external cladding and the OSB and between the plasterboard and the OSB.

Using the internal OSB technique provides more mass for better insulation performance if the room is to be used year round – a home office for example.


Tidy away the ladder and the odd tool case and it’s job done.

And the important bit.

How Much?

The materials came to £1,635.50

Labour 9.5 days at nominal £150 per day - £1,425

Total £3,060.50


Comparison prices on-line range from £7,500 to £12,000

3 - Make the lower frame

Once the Joints had been assembled the next step is to fit the connecting timbers, in this case 145 x 95 pressure treated timber, and assemble the complete bottom ring


Placing the frame into the final  position, the foundation holes were marked and the frame moved away to enable the foundations to be dug out.

6 - Fit the roof boards and felt

The frame is complete and the roof boards installed.  Note the staggered joints.

The fall of the Pent roof was created by the addition of the additional beam (95 x 45) at the top front of the main horizontal beam at the front.

The roof was completed with the addition of 1.5 rolls of anti-tear roofing felt – not the cheapest but better value.

9 - Add External Cladding

We used 144 x 20mm pressure treated timber cladding for the outside.  Less expensive materials (or more expensive) can be used, but this looks very smart and will last better than the thinner (cheaper) options.

Pretty essential for this part of the build is a nail gun.  We used a Paslode gas nailer which can be hired widely in the UK.  A hammer and nails can be used by fitness fanatics.

Contact Us

Phone : 01892 669971

Mobile : 07887 998033 ​

JointKit Ltd,

4 Clock House Court,

Beacon Road,


East Sussex,


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