Help! I'm a "you're crazy" HOB with a limited budget and pension income. I really want to use Hempcrete walls.
I need referral to Structural Engineers with experience with Hempcrete (and, less critically, disabled-accessibility) for an elevated 2 bedroom home.
The staggering $$$ quotes that I have received so far include the cost of them 'learning-on-my-job'.
Gold Coast/Tweed/Byron locals would be preferred, but not essential.
Who have you used, who do you know??
Tags, links, shares, referrals appreciated.
Thanks, Liz
SEQld need Structural Engineer with Hempcrete experience for elevated 2-bed HOB
(10 posts) (6 voices)-
Lizards Rest
MemberPosted Friday 4 Aug 2017 @ 2:22:23 am from IP # -
ilmessaggio
MemberWhat's wrong with this picture?....I want to own a Rolls Royce but I can only afford a Kia
Posted Friday 4 Aug 2017 @ 3:34:03 am from IP # -
Lizards Rest
MemberGee, thanks ilmessaggio.
To quote others, on whom you have also unloaded your negativity, "Really helpful advice".Posted Friday 4 Aug 2017 @ 5:26:57 am from IP # -
For what purpose do you intend to use the hempcrete ? load bearing or infill ?
If infill ,why should it concern most engineers ?
It can also be used as insulation product ,which definitely does not need engineering .Posted Friday 4 Aug 2017 @ 9:18:59 am from IP # -
Lizards Rest
MemberMy apologies, internet issues!!
Dave Lawrence ... Hempcrete won't be load bearing. It is an elevated single-level with non-slab flooring, so the Hempcrete's weight, and contribution to supporting the structural framing, will affect the engineering for the foundation (negatively) and anchoring of roof (positively), and for wind-bracing of walls (positively). Finding and engineer who won't need to charge me for their research to understand and calculate this, would be helpful.
Axess ... I have asked this same question of a hempcrete group. Few responses, but one which I have followed-up, this afternoon.
I like Hempcrete ... combined thermal/acoustic insulative and thermal mass properties; it breathes in CO2 and hardens over time, air-moisture balancing, fire resistant, termite resistant, other vermin discouraging, looks organic with striations of greige colour variations with each layer poured, purposefully or incidentally. Industrial hemp is grows quickly and uses less irrigation and pest control than other crops, if any! It should be used to replace many other crops and oil-based products for food, cloth, containers, construction etc.
I like rammed earth, but not on elevated foundations!Posted Saturday 12 Aug 2017 @ 8:38:55 am from IP # -
DavideM
MemberHi Lizards Rest. I might be too late to help you with info but here goes.
I doubt there are any structural engineers with knowledge of hempcrete but you should start with someone who is good at timber design. Unfortunately many don't have great timber design experience outside of ordinary domestic manuals.
What you'll need to give the engineer is technical data; wet and dry mass. The engineer will need to design with timber (since steel won't like the lime binder) as the structural members. They'll need to design the bearers and floor joists to minimally sag under the wet weight of the hempcrete wall. Hempcrete will eventually dry out (to ~30% moisture content) but it may take months depending on the weather and wall thickness. This is relevant for the engineer needs to take into account the long term deflection of the timber so that the hempcrete don't crack under too much sagging of the bearers and joists. Bearers are allowed to sag up to 12.5mm over the span - ideally I would not want more than 3-5mm sag under hempcrete so you beef the size up over and above a normal house design.
Also if you use hempcrete for your floor insulation, that weight needs to be taken into account.
Hope it clarifies.
Posted Friday 15 Sep 2017 @ 2:46:50 pm from IP # -
Lizards Rest
MemberHi DavideM, not too late at all, unfortunately. Thanks for your guidance. I'm waiting on quotes from companies with in-house engineers. If that doesn't work I'll have to slice-up the tasks and rely on a disconnected engineer. I'll keep your advice in mind. I have the wet/dry details but had not considered the length of time that the wet weight would extend. I learn more every day! I guess time lost to research abates time lost to correcting errors during construction.
Gratefully, LizPosted Sunday 17 Sep 2017 @ 5:53:34 am from IP # -
zeemeeuw
MemberWe used hempcrete for half the walls (magnesium 'inex' panels for the other half). Earth rendered on outside and exposed or render/limewash on inside -- all breathing which is a must for the humid climate here in Byron. We love it! Apart from great intrinsic properties, the exposed hempcrete is stunning. Our builders were a young mob with the right experience and great attitude - the house won a NSW-builders award on sustainability (not just because of hempcrete). The cost per m2 is comparable to brick veneer. Unlike e.g. rammed earth, labour is not heavy - we (over 60) plus fiends happily contributed to pouring and tamping under guidance of builders and saved labour-$$
http://www.abc.net.au/news/2017-09-18/high-hopes-hemp-could-revolutionise-australian-building-industry/8954994
Good luck!Posted Thursday 23 Nov 2017 @ 11:44:49 pm from IP #
