Cavity block wall height

[3ps]

Hi,

I am planning to replace my boundary fence with a wall. Only have it 7-8 years and too much of it is rotting and coming down in high winds.....

There already exists a cavity block wall for certain portions (single cavity block wide, piers, rendered one side).

The site is sloping from left to right... probably 7-8 foot over 50-60 foot length. If you stand on the sloping land, the existing wall is 6 foot high. On the other side of the wall is my patio, dug into the slope, so the wall appears about 8 foot high.


I would like the new wall to be ~6 foot high, when standing on the sloping land.

I am OK with doing this myself, over time.

However, in one spot, the neighbours behind me have cut into their garden to level it for their patio, pretty much right up to my border, and have a solid block wall built to retain my soil. It's hard to me to see this wall exactly as they have a shed, oil tank, and general stuff all over the place, but it is probably 5-6 foot high.

This problem section is ~15foot long.

If I am to put in a wall here I will have to dig down to their level, but this will leave me with having to build a wall that is ~12 foot high, and half of it will be holding up my soil.

I'm not sure of what spec wall this section should be.

I'm on a budget and want to DIY but don't want to take any risks.

Is it OK to build a single width cavity block wall that high? If so what about the foundations?

Would it be OK to make it a bit wider, perhaps using 2 solid blocks wide, with alternating courses???


I don't want to get a local builder in to quote at this stage as I feel I am just using them to get info so I can DIY, so would appreciate any advice.

Thanks.

[Carberry]

For building a 12ft wall OR a 6ft retaining wall you should be getting a structural engineer. You definitely need one if you are building a 12ft wall retaining 6 feet of soil.

[r896neo]

I read that twice and still can barely make sense of it. 6 foot here 2 foot there 12 foot over here....any chance of a photo or even a sketch as its very hard to get an overall picture.

Basically speaking, as said above, attempting to build a wall more than 8 foot high or a wall retaining anything more than about 4 feet needs a bit of input from either an SE or someone with a decent bit of experience.

This is even more important if said wall is forming the boundary or near a boundary.

[seanandruby]

i agree you'll need to consult a structural engineer. You most likely need reinforcing in the foundations continuing up inside your wall.

[lutonlagerlout]

why not use concrete slotted posts ,2 concret gravel boards and a 1200 panel
at least its unlikely to hurt anyone if it goes
as has been said its not really a DIY job and you need an engineer to assess it
cheers LLL

[bodgeitandscarper]

I saw some pictures a while back of rsj's and sleepers, but not sure of the cost implications.

[gonchy]

I saw some pictures a while back of rsj's and sleepers, but not sure of the cost implications.

we used rsj and oak sleepers on my dads property when the retaining wall started to give on his driveway which is holding about 4ft dont think its the most cost effective way but works well been there for about 8+ years now we used 6" x 4" steels amd 8x4 sleeepers

[3ps]

Hi,

Sorry, I didn't have pics to hand.
Found yet another broken post yesterday

I knew it all along really, and you are right, the wall is going to be beyond me and I will have to get somebody in.

I will have to limit them to just doing the bits that are awkard for me to do, and then finish the rest off myself.

I think this will mean about 80-90 foot of block wall, and then a 15-20 foot reinforced section.

I will try to take pics this evening so more detailed comments can be made.