fallen fence took wall with it!

[Steve]

Hi chaps, during the recent high winds, my side fence blew over and took some of the wall with it. It actually blew into the middle of the road and a kind neighbour threw it back into the garden while I was out!

The fence has stood for 2 years through some pretty strong winds, and it is in a fairly exposed spot. Something I observed was that although I used the correct plugs and screws etc, the intermediate posts were not securely anchored to the wall, causing them to move back and forth during high winds. However, this meant that all the lateral force on the fence was transmitted to the two ends, one is the house (so can take the load) and the other was the brick pier at the end of the wall which extended up about 2 courses from the rest of the wall - I thought this would be strong enough (and indeed it has been for 2 years). The end of the fence was attached by a board to the end of the pier - the board gave it a bit more lateral strength than a post would, as it was at right angles to the fence.

Now I'm looking at re-instating the wall and fence, but wondered if there was anything I could do to strengthen it - perhaps using coach bolts through the wall at every post to reduce the lateral load on the brick pier.

Any other ideas?

What is the best mix to use on the brick pier when I build it back up? 3:1? The rest of the wall is sound, but I had noticed in the past that there was a crack along the line where the wall has fallen.










Thanks!

 

[Burnerman]

A single brick thickness wall like that is always going to be compromised, strength wise, and that fence exerts one hell of a leverage.
Best to give the posts their own support and foundation, I feel, rather than relying on straps holding it to the wall.
Drilling through the wall is a reasonable idea but that will have to be in the middle.....drilling near the top edge for example is sure to knock the top course of bricks off.
John

 

[john4703]

It might be worth considering a fence that had gaps between the boards to let the wind blow through, less wind force on whatever fixings you use.
(I'd be inclined to use long posts set in concrete in the ground and not putting stress onto the wall)

 

[Steve]

It might be worth considering a fence that had gaps between the boards to let the wind blow through, less wind force on whatever fixings you use.
(I'd be inclined to use long posts set in concrete in the ground and not putting stress onto the wall)

The fence that was here previously was that design, horizontal boards with a gap between, on both sides of the uprights so you could see through if you looked up or down through them. But I preferred this style of fence as it matches the rest of the garden.

I might consider digging down in the middle of the wall to try and sink a 4x4 post. I have a feeling there are foundations there from an old wall though - the garden was originally surrounded by a double skin wall and this wall has been rebuilt as it is at some time.

At the end of the wall I could attach the fence to the metal gate posts instead of the wall. The other side I had welded on 3 brackets for the fence to attach to, but this one I didn't. I could bolt on a couple of big brackets.

 

[gregers]

i can see a ghost in the last pic..........

are you not claiming on the insurance??

 

[Steve]

No I'm not claiming. I built the thing. And I'd rather not see a rise in my premiums. I'm going to start work on Monday to rebuild the fallen section and dig down at the end of the decking to find out what is under the wall and put in a long 4x4 post. I'll also try to drill a hole in the metal Gate post to try and tie everything together. I hope b&q do suitable brackets and fixings for this. Any recommendations for brackets and fixings onto that metal post?

 

[john4703]

It is hard to be sure but it looks as if the gate post has a plastic cap that can be removed.
I fixed my gate post to a metal fence by using part of a galvanised tie down strap from B&Q.
I drilled two 10mm holes in the strap and in the post. I stuck a nut to a length of wood with bluetac and holing this inside the post this enabled me to start it threading onto the bolt. I then used a spanner attached to the remaining length of tie down strap to hold the nut while tightening up the bolt. I used gaffa tape to attach the spanner to the bar.
It all worked for me.
(A long link to the strap is used is http://www.diy.com/nav/build/buildi...uty-Zinc-1200-x-27-5-x-5mm-Bent-150mm-9273337 described as Expamet Heavy Duty Zinc 1200 x 27.5 x 5mm Bent 150mm)

 

[Static]

Attaching a fence like a sail to the top of a flimsy 1/2 brick wall is never a good idea.

Failure point was the wall not the fixings, so either increase the strength of the wall or fix the fence to something else.. I would suggest sinking the fence posts into concrete footings and clipping it onto the wall as belt and braces..

 

[freddiemercurystwin]

The OP could fix the fence to his head. That's a very thick lump of wood.

 

[ban-all-sheds]

Failure point was the wall not the fixings

Quite clearly it is in fact mostly the fixings which failed.

And in failing, may have saved the majority of the wall.