Mechanically fixed single ply membrane systems can be installed over existing roof covers and structures if the integrity of the roof structures can be established. This is done with pull out test & or a core test. 

Benefits: 

• Save money on waste 
• Saves money on Labour 
• Enables new installation to be done without affecting the waterproofing integrity of the roof 

What is a Pull Out Test?

This process allows us to establish that the roof deck is sound without effecting the integrity of the roof:

Screw long screw into roof deck, attach Newton metre gauge to screw.

      

The gauge will apply pressure to extract the screw from the deck. If the screw fails above 2 Newton metres the area of deck is sound this process will be carried out over a number of different areas of the roof. 

Each penetration is then temporarily sealed. 

What is a Core Test? 

Purpose: To establish the build-up of a roof (different layers of material below roof cover) 

This process involves extracting a sample of the roof with a 70mm hole saw. This will extract a Layered sample of the roof build up 

From the core test we can we can determine what depth of insulation might be required to bring the construction up to modern standards. We will also know what lengths of fixings will be required to secure the membrane through the roof build up into the deck below and avoid interstitial condensation.