Notch, Hole and Chase Sizes

[TheScullster]

Hi all

Reviewing Part P last night there is a reference to Part A for notch and hole sizes in joists and chases in walls. Looked through Part A and can't find any sign of this. Am I missing something here? I have found other reference on diydoctor but not "official" data.

Phil

[John McLean]

This is approved Document A-Structure: of the Building Regulations.

.a. notches should be within the following limits:

· no deeper than 0.125 the depth of the joist · not closer to the support than 0.07 of the span. · not further away from the support than 0.25 times the span.

b. holes should be within the following limits:

· no greater diameter than 0.25 times the depth of the joist. · made at the neutral axis (where the joist is under least tension, normally at the centreline of the joist depth). · not be less than 3 diameters (centre to centre) apart. · located between 0.25 and 0.4 times the span from the support.

Note that notches and holes are not permitted in roof rafters, to prevent damage to the roof structure.

Jaymack

[TheScullster]

"John McLean" wrote

...........snip

Thanks John

But I looked through the on-line version of Part A - 2004 and couldn't find that stuff anywhere! Which year/edition did you get these from and page number? Are my glasses in need of replacement or something?

TIA

Phil