[John]

I'm going to build a small retaining wall to the side of a path, about 16" high which will be faced with slate. The existing slate 'wall' is slowly folding over onto the path. I've got the bricks from a demolished wall.

The picture should make it clear what I'm doing and why. Does anyone know if I need and special sort of cement as it will be under the soil and what mix I should use (sand to cement?) ?

Thanks

[AndyRVTR]

Hi John.. any cement should be ideal, Rugby is my prefered choice, as for mix, IMO I would opt for a 3 and 1.... thats 3 sand to 1 cement (full shovel)...

[mumofstig]

will it need some kind of weep hole, so the water doesn't build up behind it? and push it over again..........just a thought  

[John]

That was easy

I'll have to think about drainage.. I've a land drain pipe I could take into the side garden because I don't want water flowing onto the bathroom wall which is damp as it is.

I've got some lovely pieces of slate to cap the wall with as well - came off the cowshed roof when the builders redid it.

[mumofstig]

That'll be a nice way to finish it off

[Lardman]

If you're facing with slate - the orginals ? They look like they have just been dug in vertically, I wouldn't waste your nice reclaimed bricks.

Concrete strip footing, 2 block high wall - put the current slates back in vertically  and cap the lot with your cow shed slate. Will look in keeping and all the weight of the bank is taken by your concrete block wall.

[John]

If you're facing with slate - the orginals ? They look like they have just been dug in vertically, I wouldn't waste your nice reclaimed bricks.

Concrete strip footing, 2 block high wall - put the current slates back in vertically  and cap the lot with your cow shed slate. Will look in keeping and all the weight of the bank is taken by your concrete block wall.

Yes, the slate at an angle will be straightened up. Might be easier using blocks as well. It's not got a lot of force against it, just a bit much for the dug in slate over the years.

Once that is done we'll plant up with bushes that don't mind shade.

I'm also building a retaining wall to the side of the shed base but that's using rocks.. we've no shortage of rocks

[8doubles]

Yes, the slate at an angle will be straightened up. Might be easier using blocks as well. It's not got a lot of force against it, just a bit much for the dug in slate over the years.

There may not be a lot of weight of soil against it but if the ground freezes it can easily expand enough to crack brickwork.

I would replace as is but bedded into a concrete footing, it will probably outlast brick or blockwork.

[cannyfradock]

John

There is not a great depth of ground, but it will hold water (especially if there are land drains on your property) which will always try to push your wall over, so as you said a retaining wall is called for....as a bricklayer I would always go overboard where a retaining wall is required so here's what I would do.....

(presuming there are no original footings/strip foundation)....remove the soil from the side of the path to 18" wide and 10" below the path level. Pour new strip foundation (4 yards long?) 6" deep to come within 4" of ground level......the area to be concreted would be just over half a ton (cheaper to buy a bulk bag (1ton)) of all in and mix to a ratio of 6:1 (4 chippings, 2 sand, 1 cement). Lay 1 full row of concrete blocks "on flat" 18" deep (this will create your toe for the retaining wall. Next lay 1 coarse of concrete blocks 4 1/2 " back from the face of your path. Next lay 3 coarses of your reclaimed bricks to the edge of the path to bring both walls the same height. Lay some butterfly ties across both walls and lay another 2 coarses of bricks on each wall to bring you up to your required height. this way you will have bricks showing from the front and rear.

Building mortar is 4 parts sand to 1 cement

Incorporate 3 or 4 weepholes on top of the 2nd coarse.

Overboard.....I know but although I am 52 years of age, I wouldn't want anybody knocking my door in 50 years time saying...."hey mate your wall has fallen over".....they'd have to bring a shovel with them to contact me !!!

Terry

[John]

Wow - that's detailed! Thanks Terry - your advice is appreciated.

When we had our cowshed renovated we discovered that the rafters had been eaten by woodworm, the supporting purlin was rotten at both ends and hanging off the rafters and the lintels had rotted to nothing. I asked the builder what was holding it up.. his answer "Willpower!"

[Trillium]

Behind that wall, you could add several inches of gravel with a drainage lead off pipe below the gravel which should minimize any water buildup behind the wall

[John]

I've got a long length of the pipe with holes in they use for land drains that I was going to put in. The hillside comes down to the dry stone wall but I think the water carries on under the surface so I think the land drain might just reduce the amount of water hitting the foundations of the bathroom and so reduce the damp problem in there as well.
The dehumidifier is pulling out a litre a day even in this weather from the bathroom

[Trillium]

The UK gets far more rain than we do so I know I'd be doing anything that helps divert water from foundations. Hope you've got good roof guttering above that area to lead away most of the rain.

Actually the piece where the cat is walking looks a bit flat and could be its own water containment area. If at all possible you might consider building up a bit of walkway height right against the building wall so that rainwater pushes away from the building itself and can somehow channel itself to either side of the building and down the hill. I mention this because the bottom of the building looks a bit water damaged.

[cannyfradock]

John

The land drains that I have come across when excavating for new works adjacent to an old property are the old heavy walled clay pipes, about 3" thick with an internal diameter of about 1 1/2". Sometimes these have collars and sometimes they are just butted up to each other. Maybe with the movement of the wall, maybe it has dislodged them. If you end up digging a footing for your wall you may come across them and divert them, although they are normally diverted around the dwelling. They are normally between 2 and 4 feet below ground level. These original land drains carry a lot of water from the surrounding banking (even in dry weather) ...and if one is broken and you can't find it, you may end up having to silicone inject the offending wall.

Best of luck

Terry  

[John]

There's a hillside that sweeps down to the house so massive amounts of water (Wales is Wet!) on the move. We had a new drain to the rear of the old cowsheds leading to a soakaway but this is on the other side.

I hadn't connected the dots between the hill side and the bathroom being very damp until now. We've got it under control but before the dehumidifier it was wringing wet in there and I thought the toilet was leaking - just condensation, thank goodness.

The jobs list just seems to grow