Technical Guidance

Question:

With regard to fire protection and security, how should the compartment walls be constructed between private garages in garage blocks with pitched roofs?

Considerations:

• Approved Document B (England), Approved Document B (Wales), Technical Handbook – Domestic 2 Fire (Scotland) and Building Regulations Part E (Northern Ireland) refer to 60 – minutes fire protection for compartment walls between buildings.

• 30 – minutes fire protection is considered sufficient between private garages and may be achieved by providing a ceiling to the underside of the roof structure, or by extending the compartment walls to the underside of the roof covering.

• The ceiling or compartment walls between roofs should be constructed to provide reasonable security against break-ins from adjoining garages.

Answer:

1. Fire protection

Fire protection may be provided by the compartment walls, as shown in figure 1, or by use of a fire-rated ceiling, as shown in figure 2.

2. Security

It is considered that the following should provide adequate security:

• Walls – masonry construction or timber frame with two layers of plasterboard on each side.

• Ceilings – two layers of plasterboard

3. Pairs of detached garages

Fire protection is optional between pairs of private garages when their combined floor area is less than 30m2 and their construction is of substantially non-combustible materials e.g. slate, concrete or clay roof tiles and external masonry walls.

Security is still required, as described above, by use of two layers of plasterboard or one layer of plywood or OSB with minimum thickness of 6mm or 9mm respectively applied to both sides of the compartment wall.

Need to check technical accuracy of the fire requirements.