BIG garden retaining wall help please

[phillippilkington300]

Hi, I have spent all day looking for someone with the same problem but all the other FAQs don’t seem to apply to me. The problem I have is that I live on a hill side up on the moors so I have a hilly garden. To the front of my house is a small stretch of land about a metre or so from the house before a rock garden that goes down about 1 metre before my sloped lawn. I want to dig out the rock garden and build a wall up. The plan is to put in a couple plants in the wall and a small waterfall in the middle of the wall into a pond. I thought about building a simple wall out of medium density blocks leaving a small cavity and then some decorative stone as a second wall, but I understand that a metre is quite high and requires a strong deep foundation and plenty of drainage. Everything I have read seems to under the assumption that I am to build the wall then fill behind it but the land is there already. What do I need to do? Oh and I have limited funds for this project. Thanks guys.

Phill

 

[JerryM]

u really need to find some one who can do some calcs on this. i have seen books in the library which would help - depends how technical u are.

otherwise u'll need a belt & braces job and it will probably end up costing more in the long run.

for me the blockwork wall is no no and concrete would be needed or probably better the blocks that can be laid like bricks and then filled with concrete.

plenty of drainage is the way to go - the water will otherwise build up an immense pressure - like a dam. u will need gravel in front of the retaining wall to stop soil/silt blocking the drainage as it try’s to follow the water flow.

for foundation if the drainage is good then something like 300 wide by say 2ft deep would sound pretty good to me. i would probably put some steel bar into the concrete to tie it in to the wall brickwork when laid.

in terms of build u need to lay it all out on the ground using line, and then dig the foundation.

i presume u are "cutting" into the existing "land" when u say its already there. in this case u will need to excavate back into the ground until u get the right position to take the foundation and wall height to give the required finished level. u then need to backfill with gravel over/around the drainage before putting the excavated soil back to level off.

hopes this helps but i'm no expert on this.

 

[noseall]

y.o.u. is not spelt 'u'.

i hate txt.

rant over.

if you can, build the wall in dense 7n blocks laid flat. you will then be able to do what you like regards a decorative masonry finish. just leave a few tie wires in the wall that's all.

the found's will need to be at least 300mm wider than the wall, giving the structure a 150mm projection of concrete beyond the inner and outer leaves. dig down to good ground and provide a minimum of 9" of concrete.

locate the wall in a practical position. common sense would say build the wall in such a way that you don't have to move much earth but afford the brickie a decent working space, particularly when building the inner leaf.

 

[Shytalkz]

Can use 3.6 strength blocks in the manner that Nose suggests, although I know he prefers 7s, as they are less prone to cracking. Put the blocks more towards the rear of the foundation (say leave a 50 projection), cuts down the bearing pressures on the front end of the footing once you've backfilled behind the wall.

 

[JerryM]

thanku Noseall

Phil,

you have got the real men helping now and i would do exactly as they say.

had an out of the box thought over night - on motorways you often see large masses of stone sitting behind steel mesh. a civil friend told me these are effectively retaining walls. i think called "corbel" - i don’t believe you would need the mesh given the height.

i think in simple words its a dry stone wall built on a slight angle. No foundation, lorry to tip and a few friends to help build.

 

[Shytalkz]

They're called Gabions, Jerry, but you were close. Sort of: your version had a "b" in it, at least .

Make a series of cages from mesh, fill with stone, place. Self weight of the whole provides resistance to overturning and sliding. Mesh contains the stone, otherwise it would end up all over the carriageway, where us speeding motorists aka adult yobs on our fast bikes with loud cans and small number plates wouldn't have enough time to react to avoid them. Joe-90 would be fine, naturally.

 

[JerryM]

Shytalkz,

Gabions - how could i - knew either "you" or noseall would sort me out on the name.

ps would not have put you down for 2 wheels though - SE's being very risk averse. i still yearn for the 2 stroke era but the bikes have gone and so have my reaction times.

 

[Shytalkz]

Heaven forbid the day that someone ever accuses me of being a normal SE....

 

[noseall]

thanku Noseall

 

[chessspy]

Use conkers, laid flat, make sure you cut enough earth back to leave a 4" gap behind the retaining wall and after a few days fill the void with gravel or ballast or chalk type1 etc.
you need to trap some pipes in the wall to duct the water through close to the bottom 2" waste is ok that will prevent water build up behind the wall.
If you use a 5-1 mix it will be tremendously strong.
You can 'pretty up' the face by any method you chose thin slabs of york stone laid to a random pattern on edge looks good, so embed some expamet in the bed joints of the conkers on the face side to grip the facing work short strips of 6" wide 18" long and 3" showing, every so often is ok.

 

[phillippilkington300]

All good stuff peeps, I'm really greatfull. Keep it comming it's all good.