Extension Project Start
© P. DingleyMay 23rd 2004, work commences on the new extension to the main Sherwood Observatory building with a few of the active society members starting to break up the existing concrete base at the side of the building, and dig out the foundation trenches. Now completed the new extension provides a workshop, a wheelchair friendly access ramp into the premisis, and a fully equipped disabled toilet.
Trench Collapse
© P. DingleyJune 4th 2004 - One of the difficulties with digging foundation trenches on the site of the Sherwood Observatory is that with a sand-layer, and a lot of infill ground the trench walls can easily collapse into the excavations.The image below shows the state of one corner of the foundation trench after a little overnight rain caused a minor collapse. Luckily there was no damage to the pale coloured soil-pipe that leads from the W.C. to the cesspit, so all that was needed was to re-dig out the collapsed area (not for the last time).
Onward and Downward
© P. DingleyAfter a couple of weekends of digging the foundation trenches are down to about 4-feet and ready for the first check by the buildings inspector.Had we have known at this stage that we were going to have to dig out another 3 or 4 feet we'd have probably hired a mechanical excavator!
Onward and Downward
© P. DingleyAngus inspects the work on the foundations for the new extension workshop as they gradually get deeper and deeper.Two poles (which can be seen at the end of the trench), are used in conjunction with a 50-foot length of clear pipe and a lot of blackcurrant juice to check that the foundations are being dug to the same level at both ends of the building.
The wooden beam visible spanning the far end of the trench, has been temporarily installed to bridge the gap to the front door of the observatory whilst excavations continue.
Foundation Blockwork
© P. DingleyThe first layer of blocks are laid on top of the concrete foundations.Once up to ground level engineering bricks will be used to take the extension up to the damp-proof course, before switching back to larger blocks again for the rest of the construction.
The Workshop wall (pictured here) will also have an access ramp installed, providing easy access to the observatory for anyone that uses a wheelchair.
Preparing for RSJ Installation
© P. DingleyJuly 2004.Garnett uses an impact hammer / breaker to cut a hole in the outer lecture room wall of the existing observatory.
Once the three holes have been cut in the wall the 5 inch concrete base (which Garnett is standing on) between the new holes and the outer extension walls will be manually smashed and removed, then three RSJs will be inserted to help support the new floor of the workshop.
RSJ Installation
© P. DingleyJuly 2004.With the main foundations dug and filled with concrete, and the external walls for the extension built up to the damp-proof course, the time comes to install three RSJs (Reinforced Steel Joists) which will help support and stabilise the floor of the new observatory workshop.
The local buildings inspector insisted on the building incorporating these RSJ supports because the ground in the area of the workshop was built-up and levelled with in-fill from the original observatory construction.
Eventually these RSJs will be covered with a layer of concrete, laid on top of a damp-proof membrane.
Extension Project
© P. DingleyJuly 2004.With the foundations dug and the concrete laid, work starts on the brick-work to bring the walls up to the damp-proof course level.
As the height of the walls increases the existing outer-porch will need to be demolished to allow access to the inner walls of the extension.
Taking Stock
© P. DingleyGarnett washes the area around the inner foundations so that they can be more easily seen by the buildings inspector while Gordon discusses the work completed to date.The original target was to build the foundations to ground level by the end of the year (2004), so after a couple of months work the project is already well ahead of the plan.
Taking Stock
© P. DingleyGarnett washes the area around the inner foundations so that they can be more easily seen by the buildings inspector while Gordon discusses the work completed to date.The original target was to build the foundations to ground level by the end of the year (2004), so after a couple of months work the project is already well ahead of the plan.
