Suspended Timber Ground Floor Joists

This floor insulation method is commonly used for upgrading the thermal performance of existing timber floors as it has no impact on floor levels.

Suspended timber ground floor joists.

Ground floor hollow or timber floor. The ends of these timber joists are built into or suspended by joist hangers from the external walls of the property. These can be classed as either suspended or solid. A suspended floor is a ground floor with a void underneath the structure.

However the floor structure is supported by external and internal walls. Concrete vs timber floors. These floor joists are raised above the subfloor on small supporting walls called tassel walls or sleeper walls. This creates a small gap and allows ventilation and air movement to prevent damp forming in the timber joists.

Hollow floors also known as suspended or timber floors are simply timber joists suspended across and supported by load bearing walls under the floor. The simplest way of insulating suspended timber ground floors is to fit insulation boards between the joists and support battens. Solid floors are a lot more substantial and require the ground to be made up in layers of ground sub base sand compacted hard core damp proof membrane insulation and concrete. If the ground floor in question is of a suspended timber construction and whether this is a renovation or new build project then the insulation would normally be installed in the joist zone that is installed between the joists.

Suspended timber floors need to have spaces underneath ventilated via air bricks through the outer walls and gaps in any internal walls so that the air can move across the building underneath the floors to prevent the build up of moisture in the timber which could lead to fungal attack. Suspended timber ground floors consist of the finished timber floorboards being attached to floor joists which are suspended above the subfloor of the foundation. There are 2 types of floor construction used in the building industry today. Ventilation is required in the same way as a suspended timber floor.

Suspended timber floors which are typically found in older houses are normally made from timber floorboards which are then attached to joists just above the foundations of a house. The floor can be formed in various ways using timber joists precast concrete panels block and beam system or cast in situ with reinforced concrete. They can normally span greater distances than timber joists. Previously floor timbers had been prone to damp and rot thanks to their direct contact with the moist ground.