Engineering plans - Should I be annoyed? What can I do?

I have just received some engineering plans for a garage and decks project. Please excuse any errors in terminology as I have no background in building etc.

The plans given to the engineer state things like "standard construction timber frame" and to "AS 1684". I did indicate verbally that I was looking for a basic construction, the plans are the only written indication of wanting standard construction however.
I've spoken with my builder and the engineering plans received ask for thick hardwood timber for the entire construction, anything but "standard" in his opinion and add significant cost. My builder queried some of this with the engineer who said yes standard treated pine would be suitable (or thinner hardwood) which resolves some issues - but why would the engineer use thicker more expensive materials for "standard timber construction"? Still trying to establish why the engineer wants a concrete slab under the second deck as he is now away.

Also I was told "Your plans have been completed" (in email) and will be released once they received payment in full, which I promptly made. Only the deck plans were ready and the garage is listed as "stage 2" even though it is one project (one deck meets the garage).

How would you proceed?

 

I know quite often engineering can be 'over engineered' for often no good reason, adding unnecessary cost. It's why I like to engage engineers who work closely with my builder if possible.

I dont know if your job is over engineered or not ( out of my sphere of expertise) but if your builders engineer is confident you can use cheaper materials etc to get it over the line then perhaps make the suggestion ( tactfully) to your engineer to see if he can change his engineering specs .

 

AS1684 is the timber framing code. It has a series of load and span tables. If one timber grade will so the job, so will a few others in different sections and stress grades. A lighter piece of F22 hardwood vs a much larger F7 MGP.

Dumb question (as I haven't required at engineer for a garage for a while) why didn't the engineer stick with the slab design & tie downs, then use the builder to select the appropriate timber framing to the code?

 

Did you make it clear the budget was for the completed build and not just for his engineering plans ?

 

From what I have heard/seen in emails the engineer said it is fine swapping out same dimension of hardwood for pine and it is still suitable.

I have no idea, my builder thought it was strange. I didn't know what to expect so I just asked for the engineering required for the construction of what the drafty had drawn up, it is new territory for me and hadn't engaged a builder at the time to help guide me.

Sorry not sure what you mean. Drafty, engineer and builder are three separate parties which seems to not be ideal. Engineer quoted on just the engineering plans, stated they were completed and then only provided half of the engineering plans on payment and that the rest were still been done. Prior to payment the engineer clearly stated the plans were finished and payment was required. Written agreement states initial payment and then balance on completion of plans to release plans.

My builder has sent an email with further suggestions to the engineer. last email the engineer sent before going away was that a slab was required as the deck may not be high enough off the ground (stating 400mm clearance required for timber construction without slab, with no reason). Builder stated only 150mm clearance is required to avoid termite inspection so he has no idea why the engineer might be asked for a slab without 400mm clearance.

 

The reason that the engineer specified hardwood is durability, weather & pest resistance. Treated pine may offer some of these but in much deeper or larger sections of timber, hence the additional ground clearance required.

 

Not sure what this means?

 

400mm clearance isn’t only for termites but also for ventilation. Timber can become damp and start rotting if it’s too close to the natural ground level.

 

Steel framing and powder-coated steel posts. Pricey but an acquaintance went they way for his decks. More than likely the frame work will still be there after the rest of the house falls down.

 

I spoke with the engineer. The hardwood was specifically for fire ratings which aren't actually required, they hadn't read the specs/council approval I initially sent or done a 2 minute check/call to myself or certifier, just assumed they might be required.

Thanks.

Everything is cleared up. Seems everything was just assumed for worst case rather than making a phone call/email to confirm details.