External Timber clad

[Aleeex]

Hi

when designing a small residential property with external timber wall clad and masonry, should you consider the external wall against lateral forces?

 

[Aleeex]

I designed the wall for 1 meter length, and the horizontal bending moment due to lateral force is less than the wall capacity. If I design the wall spanning vertically, adding the wires will not help as it will still fail. As I said, I considered the wall edges are all supported. Therefore, the horizontal bending not the vertical dictates the design in terms of horizontal loading check.

 

[BAretired]

I designed the wall for 1 meter length, and the horizontal bending moment due to lateral force is less than the wall capacity.

But you don't have supports at l meter centres, so your design assumption does not conform with reality.

BA

 

[Aleeex]

What do you suggest? Design the wall for 7m length?

 

[Aleeex]

If I am going to design for 7m length,I have to add wind post in the middle.

 

[BAretired]

If I am going to design for 7m length,I have to add wind post in the middle.

That is one option. It works fine and gives you a horizontal span of 3.5m. If it is located inside the wall, it creates a projection which may be architecturally objectionable.

Alternatively, you could use a vertical support in the space between the masonry and the timber cladding.

A second alternative is to reinforce the wall as suggested by jayrod12, i.e. using 1-15mm reinforcing bar spaced at 1200 o/c, filling that cell with concrete.

A third alternative is to use a wood stud wall and forget about masonry altogether. That is probably what I would do but I live in Canada and you live in England where the economics may be different.


BA

 

[Aleeex]

I might use wind post C channel 105 x 60mm it is not going to create projection as the wall 140 thick, however, what should I fill the gap with behind the post e.g 140mm - 105mm =35mm gap?

 

[BAretired]

Good question. Also, how will the flat side of the channel support the wall? The detail needs some thought.

BA

 

[Aleeex]

The wind post is going to be strapped to the roof joists.

 

[BAretired]

The wind post is going to be strapped to the roof joists.

Okay, but that doesn't address the question of how the flat edge of the channel provides edge support to the wall. You could provide dowels through the channel to align with joints in the masonry. Then you could fill the gaps around the channel with mortar.

BA

 

[Aleeex]

We use wall ties here.

 

[BAretired]

Okay. Can you provide a sketch showing the plan detail of the channel and wall?

BA

 

[Aleeex]

What do you think?

 

[BAretired]

I assume that the wall ties are welded to the post in the shop (not on site). The gap between the flanges of the channel should be filled with mortar. The 35x60 mm mortar inside the channel flange should have a light mesh or metal lath tacked to the channel to prevent it from falling off.

The connection at top of channel should be adequate to resist wind force inward and outward. Wind pressure can be in both directions.

BA