Gavanised beam or not.

[Screech20]

Hey guys and girls.

I’m just looking at ordering the beam for over our bi-folds.
It’s a UB with plate welded to bottom at take the external blockwork.

Would galvanising really be necessary for this?

The suppliers asked if I need it to be and said it needs it if it’s outside. Strictly speaking, it’s not outside, is it?

What’s best for it in the cavity?

Thanks!

 

[John D v2.0]

It does need to be protected in some way if it's likely to be damp, ours came with that red oxide primer paint, although most of them were within the insulation layer so it didn't matter. That was all in the designs from the SE though

 

[^woody^]

Whoever specifies the beam should specify the performance and hence the coating.

 

[tony1851]

Galvanising on its own does not help; over time, the mortar becomes slightly acidic and begins to attack the zinc.
As you are using a fabricated steel beam, best treatment is a couple of coats of red oxide, PLUS, the builder should incorporate
a flexible dpc over the top of the steel to protect it from rain getting into the cavity.

 

[Leofric]

There is another similar topic on here where they are getting in all sorts of trouble because the construction details were not sorted out before work started on site. Have you had any drawings /construction details prepared and approved for the structural work under building regulations? Has a structural engineer calculated the beam size and specified any concrete padstones for the beam to sit on ? Other things to consider are dpc tray over beam and weep vents in vertical mortar joints, minimising risk of condensation due to cold bridging across steel.

 

[Screech20]

Thanks guys.

The SE has specified the beam and said it needs to have adequate rust protection to satisfy building regs.


Thanks

 

[Leofric]

SE didn't say what that meant then ! i.e. what sort of rust protection - wasn't that part of the original question ? I would say red oxide paint but tell the SE to specify the finish for you to submit to Building Control.
Regards

 

[John D v2.0]

The SE has specified the beam and said it needs to have adequate rust protection to satisfy building regs.

In other words he said "not my problem". Not much use!

 

[Notch7]

I have to say Ive not noticed finish specified on structural cals / drawings.

Ive always painted red oxide on them.

 

[Leofric]

Any silly bugger can just say 'adequate whatever to satisfy building regulations ' !

 

[noseall]

We always opt for the grey primer. More classy.

 

[catlad]

Classier

 

[Keithmac]

Primer is normally porous..