Another Q on screw fixing external wood cappings

[rick]

Week before last asked some advice on how to fix Tanalized 50mm thick wood capping onto brick/block wall. (60m of it)

Final decision is to fit with Concrete screws .. Frame Screws

Managed to get 150mm length at only £13 a 100

Good suggestion I have had is to insert 5mm thick plastic spacers under wood to keep off brickwork when damp and also allow for any irregularities when fixing .. so may take that approach.

My question is two fold ....... first off at what centres should I put in these fixings ... thinking that 600mm c/s may be suitable ? someone mention 2 fixings every 600c/s but that seems a lot of screws.

I had thought about counter-bore and then plug ...... a lot of effort, if I instead just pulled in screw to below flush and fitted a cover cap. Such as:

Which are specifically for concrete screws .....Thoughts ?

Know of a better approach ?

[rick]

That is not much use .... I couldn't use concrete cappings easily as overhang would be too great ... in any event I have bought the wood.

Don't know why you think it will only last 18 months. Fully pressure treated Tanalized timber plus finish coating on top will last a lot longer than that ..........

[harry]

Tanalising is not what it once was. It used to be effective when it was arsenic based. Then is became copper based. Now I think it's chromium based. Very poor now compared with the orginal.

[rick]

same as cresote ... the current ver creocote is not as good ......... but if product has heath risks they have to cease its use.