Chippings on flat roof - how deep?

[MattJD]

Hello and apologies if has already been written, i've used the

and cant find the answer!

Brought my first house and have been doing some repairs to the crusty old flat roof (vendor told us it was replaced 10years ago - i somehow doubt that!). Started to sweep the mossy area and found about 2-3cms of chippings on there, how deep should this layer be?

Don't really want to use solar reflective paint as the bedroom looks out onto this roof so cant sweep it clean



Matt

 

[breezer]

depends on size of chippings.

its actualy there to prevent sunlight damage to the flat roof.

2cm of small chippings sounds fine

 

[MattJD]

They are small chippings, so 2cm it is!

Thanks for the reply

Matt

 

[bendylow]

considering the different sizes of lime chippings available the depth is irrelevent,you need to make sure the roof is completely covered, most flat roofers work on 1 bag of chippings covering 3 square metre's.the most common sizes are: 3mm(very dusty),6mm(most popular)and 10mm(too coarse,easy to puncture roof covering when walking on them).