Suspended Timber Floor Build Up

This moisture build up can cause deterioration not only the timber joists but also any coverings placed over the joists.

Suspended timber floor build up. However the floor structure is supported by external and internal walls. A suspended floor is a ground floor with a void underneath the structure. The ends of these timber joists are built into or suspended by joist hangers from the external walls of the property. Hollow floors also known as suspended or timber floors are simply timber joists suspended across and supported by load bearing walls under the floor.

To support partition walls and accommodate openings for staircases for instance the rule of thumb is for joists to be doubled up although building control will want to see the structural engineer s calculations to confirm adequacy. The joists are typically laid across the shortest span. Ventilation in suspended timber floors can be achieved by installing vents below the joist level in opposite walls of the building and if possible on all sides of the building see figure 1. Make sure that the air vents in the crawl space below the membrane and insulation are not blocked and that there is plenty of ventilation to help remove any moisture under the floor.

At the turn of the 18th century when construction techniques moved from boarded floors installed directly on the ground to suspended timber floors over a ventilated chamber the innovation solved a significant problem. Suspended timber floor as a requirement of the building regulations the structure should be protected against the growth of weeds and other plant life. Previously floor timbers had been prone to damp and rot thanks to their direct contact with the moist ground. Water systems retrofitting a floor heater with the original timber floorboards as opposed to a new timber floor finish can make for a complicated project.

Suspended timber floors are a common structural element in many period properties and we offer a range of floor heating systems specifically designed for suspended timber floors. 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. Ventilation in floors especially suspended timber floors is very important so as not to facilitate the build up of moisture within the floor structure. A suspended timber floor is usually constructed using timber joists suspended from bearing walls which are then covered with either floorboards or some other for of boarding material.

Figure 1 floor ventilation. Time to get building again.