Is there a structural engineer in the house?

Is there a structural engineer in the house that is willing to do some cash in hand mates rates job?

I just got quoted between $1000 and $1200 to draw a retaining wall. And that doesnt include the cost of submitting to council or the private certifier coming back to tick it off. Friggin insane! The wall is 8 metres long. Starts at ground level rising to 1.1 metres at the other end. A retaining wall that contains just $300 worth of material!

I armed myself with the recommended specs and it took me about 20 minutes to draw a sketch with MS paint. Imagine how quick it would have been to do it with proper drawing program. Does anyone here have the qualifications or the will to do it for real dollars?

PS, I see Beechwood is broke. If only I could do the same to Clarendon!

Check with your council but i think you dont need council approval if you dont go over 1.2 high??? I feel sorry for beachwood customers cheers shane.

600mm here in shellharbour 👎

Not sure about your local council but up here I put in my own drawings and marked up a some notes on the drawings. The notes went to the effect of naming the product brand and style, then stated that they are to be installed as per the manufacturers specifications for the height and load rating. These details I got of CSR when getting a quote for materials. Saved me a wad of cash.😁

if its in yr back yard build it yr self stuff the enginers n council

if its out the front then different matter but u can draw it yr self

I had the same issue in Brissy. Got around it by terracing. 2@600mm walls with a garden in between instead of 1@1200.

Find out what YOUR council will allow you to go to without engineers details (most will allow 1000) then build it to the max and batter the top away from the wall, if what you need exceeds their height restrictions build another wall behind it, go back the same distance as the height of the wall at that point. If they will only allow 600 and you need 1200 then do a 600 wall and another 600 wall 600 behind the first. Unless the wall is part of your original council approval then wait till you have the occupation cert. then do what you want. If you use a manufactured system (concrete blocks etc) then the manufacturers should have the engineering you need and will usualy supply it with your purchase. Ensure you have enough drainage behind the wall, hydrostatic preasure is the cause of failure 95% of the time, can't have too much drainage, very important.

There ya go, Stanley supports my "two walls" idea.

I got my design specs from a timber yard. They gave me a document by some timber authority type organisation that tells me what spacing you need for posts of diffent sizes, depth of holes, tells you everything you need to know. So I have drawn my plans to that spec. All I really need is for some engineer to look at it and put a stamp on it. The rules in shellharbour are definitely 600mm max or it needs to be designed by a structural engineer.

For the wall across the back I have done exactly what you guys suggest. I got Clarendon to excavate down to 600 and batter it back so I only need the one wall that I can legally do myself. I think in time I will terrace it and make a garden bed out of it, but for now I'm happy with the batter.

The side is a different story. The wall has to be at least 400 from the fence line, plus the water heater is up there, so not really enough room. I dont know what the rules would be for spacing between the walls if I decided to terrace it. I dont thnk it would be structurally sound to have 2 600 walls on top of each other, though I guess I could build the 1100 wall to design spec and put another wall in front of it that only holds a narrow garden bed. Waste of money and timber but cheaper than an engineer I guess. hmmm i dunno. I'll have another look.

The requirements for a wall are in my DA. I would put it in even if it wasnt. Its definitely needed. The clay soil is solid rock when its dry, but 10 mm of rain and it falls in. Its also a condition of the occupancy certificate. I have an interim one at the moment, but cant get the final one until the wall is complete. If only I lived in Wollongong. I could have just screwed Beth Morgan and got away with it.

amazeer said

If only I lived in Wollongong. I could have just screwed Beth Morgan and got away with it.

LOL x 6
BTW do you mean you could have gotten away with the wall or the screw?

Hey amazeer,

I am a structural engineer but sorry I work in QLD.

You can get the standard spec's from a manufacturer but that is not what Council is concerned about.

Their problem is whether or not the standard details apply to your site and that is what us engineers do.

What are the soil conditions, is there going to be a fence bulit on top of the wall (that adds wind load), does the neighbours property have potential to load the wall e.g. parked VW's etc. (A kombi is a worst load than a bug..haha)

Seriously thought $1200 sounds a bit rich. Should be $200 to visit the site and see for yourself, $200 to certify your plan..$400 all up. If you want them to draw it then double that because like you say walls to that height are a standard drawing anyway but someone still has to produce the plans.

Ring Engineers Australia or try the local paper or Google and find out the names of Chartered Engineers in your area and shop around. A guy who works from home will always give a good price because he has less overheads.

Remember however Engineers all have to carry big insurances policies and these days those cost a bundle.

We have to charge a fair rate for our services.

Good luck.

Well the update is I paid my money. I found a one guy who would do it for $500, another that did it for $440.

I reckon it was a waste of $420.

The drawings I have look like they are generic. Its a cross section of a "typical wall". So basically he has copied my house plan and cut and pasted a cross section next to it. He drew the plan before he visited the site (if he visited) He rang earlier today and told me he had drawn to versions, 1 brick, 1 timber. He asked me what the ground was like. When I said rocky he then said he had better come and take a look. Whether he did or not I dont know.

Nobody needs to come and look at land at Flinders. Its rocky clay. A well known fact for anyone who lives here. This guy just got paid $440 for 10 minutes work, and the drawing I have looks nothing like a wall. Nice work if you can get it. Only good thing is that the design specs I got from timber mob said the wall had to be sloped back 1 in 10. This drawing has it vertical. Which is a good thing, will be much easier to get it perfectly straight, which my OCD would insist on.

Perhaps you can answer me this question though....
On my drawing I had the wales made from 150 x 75 timber. Apparently they are not strong enough and he has put 200 x 75. To me that doesnt really make sense. I would have thought that 4 off the 150 x 75s would have been identical to 3 off 200 x 75. This is no big deal either way. The larger timber is a bit more expensive but you need less of them so it works out very little difference in total cost.

Anyhow, I am glad that shit is over and I can just start building this damn thing and be done with regulatory bodies.

amazeer wrote:Perhaps you can answer me this question though....
On my drawing I had the wales made from 150 x 75 timber. Apparently they are not strong enough and he has put 200 x 75. To me that doesnt really make sense. I would have thought that 4 off the 150 x 75s would have been identical to 3 off 200 x 75.

You are correct...no difference.

For wales it is the 75 dimension that controls. A 200 wide wale will pick 200 of soil load but is stronger being 200mm wide. Same proportion as a 150 which picks up a 150 of soil load etc.

Different story if it is for posts as the 200 is stronger than 150 obviously.

Sounds like this guy is a w*nker but at least you are building.

Unfortunately you may need him to sign off on the finished wall.

Try and get a Council inspector as he should be cheaper.

The difficulty is that a Council inspector will not approve the wall if you have changed from the approved plans and he will tell you to go back to the engineer if you have changed something.

A rock and a hard place.

Only just saw this. But sounds like you worked it all out.

I would personally double check your drainage, its very very important......

Best of luck.