Diary Entry No.3 – Foundations

In our last diary entry, construction of the pavilion had begun with the contractor stripping the existing concrete and substructure to lower the site levels to allow the foundations to be dug for the arrival of the ‘Glulam’ frame and the fitting of the SIP in the New Year. This month saw the contractor start to pour the footings and start work on the pavilions’ block work substructure. The contractor has had relatively good weather to date which has eased the working process.

Concrete has been chosen to construct the floor slab for a number of reasons. Costs were a major factor in the decision as it provides the cheapest, quickest and most accessible material available to the team. The contractor is also familiar with the concrete construction processes.

The substructure includes block work, compacted hardcore (crushed stone), binding was then applied on top of this alongside a damp proof membrane. The concrete sub floor was then poured on top. This layer of concrete has to sit for a few weeks until it totally sets before any other work proceeds.

In order for the building to perform as efficiently as possible, the choice of material is crucial to reduce and if possible eliminate thermal bridging. As we progress through the build we will discuss in depth each of the construction elements and how they help increase efficiency.

The following detailed drawings illustrate the construction method for the foundations and how the ‘Glulam’ frame and SIPS wall panels are connected to them.  The foundations are poured in two sections, a trench fill foundation that the has a separate concrete topping foundation poured on top with a layer of reinforcing mesh included between the two layers for added strength.  The ‘Glulam’ frames are then bolted to the concrete of the foundations using a thermally broken fixing and the SIPS panels are fixed to the structural frame.

To avoid thermal bridging from the foundations to the structure of the building, the product utilised for this element of the construction is ‘Quinntherm’ insulation blocks.  ‘Quinntherm’ insulation blocks are a very high density speciality product used to eliminate thermal bridging in the superstructure of a building. All sides of the blocks are bitumen coated to protect them and the upper and the lower surface of the blocks are additionally coated with a glass reinforced fleece.

After checking our details through the thermal bridging software we could accurately establish what thickness of thermal block were required and where it should be located.  For this project we used three layers of ‘Quinntherm’ blocks for the outer perimeter walls with the SIPS panels constructed on-top of them.

We’ve also included the following photographs illustrating the foundations being dug out in preparation for the pouring of the foundations.

The next stage on site will be the erection of the ‘Glulam’ frame followed by the fixing of the SIPS panels