Browse Forums Building A New House 1 Jul 01, 2008 1:43 pm Hi everybody,
I know this would be far better if I could scan the plan in but work with me here. And please excuse my "technical" terminology. In the house I am to build, I have chosen to have the slab extended to under the alfresco area. This area is 4.5m x 6.5m approx. On the preliminary footing layout plan, the waffles don't extend to the alfresco area. Overall the house will have 43 concrete piers and some are where the house proper meets the alfresco. The exposed edge of the alfresco slab (being that it doesn't adjoin the house) will be bordered by strip footing. Is this normal practice when I am paying for the slab to extend to the alfresco or should the waffle construction that will be used as the foundation for the rest of the house simply extend to the alfresco area? I know this is probably as clear as mud but I resisted the urge to use the word thingy! So that's something. Any help or clarification would be most appreciated. Jo I leave you to fend for yourself, figure things out yourself. Terrence Malick Re: For TDL or any other engineery types. 2Jul 01, 2008 1:48 pm Absolute total guess (as I'm not an engineery type) but could it be because the alfresco slab won't be carrying as much weight as the rest of the house? [sneakersss] Re: For TDL or any other engineery types. 3Jul 01, 2008 1:56 pm This is the back of your house....right?
http://i241.photobucket.com/albums/ff2/mikeb1968/GrandviewAlfresco.jpg Three adjacent walls (left, right, and bottom) are supported on the houses' waffle slab. Loads are transferred from the roof, through these walls, onto your waffle slab. Therefore apart from a keg of beer there are no heavy loads on the alfresco area. To think of it another way, it would be perfectly acceptable for them to leave the alfresco area bare, and for you to pave it, deck it, or leave it as it is completely independent of the house. So all they are doing is chucking a slab of concrete down for you 'fresco. mmm....donuts Homer Simpson 1956- Links: Site Costs Ready Reckoner | H1 Addiction Medical Advice | Château TDL: The Backyard Re: For TDL or any other engineery types. 4Jul 01, 2008 1:57 pm or.....what YSSIM said..... mmm....donuts Homer Simpson 1956- Links: Site Costs Ready Reckoner | H1 Addiction Medical Advice | Château TDL: The Backyard Re: For TDL or any other engineery types. 5Jul 01, 2008 2:00 pm Good point missy. I thought about that but then the same principal would apply to the portico (1.5m x 4.5m approx) and that is the waffle construction. I can see the logic in your thinking though. Another guess? I leave you to fend for yourself, figure things out yourself. Terrence Malick Re: For TDL or any other engineery types. 7Jul 01, 2008 2:08 pm So Mike is it still as structurally sound as the rest of the slab? The reason I chose to do this is because the block slopes and I didn't want cracking problems in the future and this way it was all under warranty, etc, etc.
I see what you and missy (trainee engineer!!) are saying, but why wouldn't that theory extend to the portico? It wasn't cheap to go for this option and I want to make sure I'm not in effect paying an enormous amount of money for a bit of concrete. I just want to know that if I'm paying for a structurally sound extension of the slab, that's what I'm getting. I'm not stressing about it, just trying to understand. I leave you to fend for yourself, figure things out yourself. Terrence Malick Re: For TDL or any other engineery types. 8Jul 01, 2008 2:08 pm joles Yeah that's the back of our house except the alfresco has been extended out a further 3metres. The extra depth doesn't matter and the portico is entirely different, it carries the weight of the portico structure, plus you columns into the floor slab and therefore needs to be a stiffer slab. If it wasn't it would break in half. They could but foundations in for the piers alone and still do an infill slab. But give it six months and your portico slab would look like crazy paving with all the re-entrant corners (corners that stick into a slab). http://i241.photobucket.com/albums/ff2/mikeb1968/GrandviewPortico.jpg mmm....donuts Homer Simpson 1956- Links: Site Costs Ready Reckoner | H1 Addiction Medical Advice | Château TDL: The Backyard Re: For TDL or any other engineery types. 9Jul 01, 2008 2:15 pm joles So Mike is it still as structurally sound as the rest of the slab? The reason I chose to do this is because the block slopes and I didn't want cracking problems in the future and this way it was all under warranty, etc, etc. I see what you and missy (trainee engineer!!) are saying, but why wouldn't that theory extend to the portico? It wasn't cheap to go for this option and I want to make sure I'm not in effect paying an enormous amount of money for a bit of concrete. I just want to know that if I'm paying for a structurally sound extension of the slab, that's what I'm getting. I'm not stressing about it, just trying to understand. One thing I'd ask re: the rear alfresco is there there is a joint along the red line I've shown below... http://i241.photobucket.com/albums/ff2/mikeb1968/GrandviewAlfresco3.jpg Inevitably the alfresco slab will crack it will "hang up" on the three sides and settle a little towards the back so most likely the slab will crack along that red line.....concrete does that.....it's controlling the cracking so it doesn't look crap later on that's important. If they "pre-crack" it along there with a concrete saw then it's less likely to crack all over the place later on. Is this making sense or did it sound like "blah blah....concrete....blah blah...crack....blah blah....thingy". As far as "structurally sound" goes....it's not as strong as the house slab, but then it doesn't need to be. mmm....donuts Homer Simpson 1956- Links: Site Costs Ready Reckoner | H1 Addiction Medical Advice | Château TDL: The Backyard Re: For TDL or any other engineery types. 10Jul 01, 2008 2:18 pm Our portico is different to that. ours extends across in front of the bedroom.
Anyway, I understand about the portico, but the reason I mentioned about the extra depth on our alfresco is because the depth changes things. The load is no longer bourne only by the three walls of the house. The extra depth means there are two piers in the corners that have to bear some load (similar to the portico). So the alfresco slab with the extension bears some load whereas a slab in the standard alfresco area wouldn't. Does that make sense? I leave you to fend for yourself, figure things out yourself. Terrence Malick Re: For TDL or any other engineery types. 11Jul 01, 2008 2:21 pm Do the alfresco piers have their own footing? mmm....donuts Homer Simpson 1956- Links: Site Costs Ready Reckoner | H1 Addiction Medical Advice | Château TDL: The Backyard Re: For TDL or any other engineery types. 12Jul 01, 2008 2:28 pm It doesn't say anything about footings. It says, "90 x 90mm timber posts on galv. stirrups encased in brick piers." (Are they footings? )
As I said before, the three sides of the alfresco extension that extends in to the backyard have "strip footing 300mm x 450mm (min) deep with 3-L12TM top and btm." I leave you to fend for yourself, figure things out yourself. Terrence Malick Re: For TDL or any other engineery types. 13Jul 01, 2008 2:38 pm Yep...it's onky dorey....
They're putting in strip footings on three edges.....sorry missed that part....the 3-L12TM is the reinforcement required on top and bottom (btm). Your roof will be held up with timber posts. The posts sit on a stirrup which is cast into the concrete. They then clad it with bricks to match the house. mmm....donuts Homer Simpson 1956- Links: Site Costs Ready Reckoner | H1 Addiction Medical Advice | Château TDL: The Backyard Re: For TDL or any other engineery types. 14Jul 01, 2008 2:42 pm So do I still have to worry about that cracking in the middle of the slab? And is it for all intents and purposes as structurally sound as the waffle slab? This is really important as there will be tiles going down on the alfreso slab. Should the tiling be postponed for a certain period of time? I don't want cracked tiles six months after I move in. I leave you to fend for yourself, figure things out yourself. Terrence Malick Re: For TDL or any other engineery types. 15Jul 01, 2008 2:52 pm It sounds structurally sound....they've done what you would expect them to do.
Re: tiling.....I don't think there's a magic answer....and I think you'll get different answers and it would be good to get people's experiences here. Personally, if it was my house I wouldn't put any tiles on an external concrete surface for a cycle of wet and dry weather (six months is a good figure). Internal is not a problem as there's very little moisture change underneath. This gives an opportunity for the slab/house to settle a bit (which is natural) and less chance of cracking your slab covering. As I said that's personal opinion - not necessarily science - and it may be a bit conservative. mmm....donuts Homer Simpson 1956- Links: Site Costs Ready Reckoner | H1 Addiction Medical Advice | Château TDL: The Backyard Re: For TDL or any other engineery types. 16Jul 01, 2008 3:00 pm Thanks so much for your help Mike. As I said, wasn't stressed just wanted to understand why the construction was different and I wanted an answer from someone other than the builder. Feel confident I've done the right thing, so thanks for your time.
Now get back to trawling the internet for a discussion piece for tonight! Thanks Jo In for a penny, in for a shake of a lamb's tail! He who is without sin, should cross that bridge when he comes to it! (my fave) I leave you to fend for yourself, figure things out yourself. Terrence Malick Re: For TDL or any other engineery types. 17Jul 01, 2008 3:04 pm No wuzzas:
My favorite: Like a blind man, searching for a black cat, in a dark room......that isn't there. mmm....donuts Homer Simpson 1956- Links: Site Costs Ready Reckoner | H1 Addiction Medical Advice | Château TDL: The Backyard Re: For TDL or any other engineery types. 18Jul 20, 2008 5:09 pm Mike just further to this, they have acknowledged that it is a pricing mistake as we have been charged for the full waffle slab construction but that is not on the engineering plans.
Am I right in assuming that if it is upgraded to a fully integrated waffle pod construction, this would be ready to go for any further extensions by us or any future owner? For example, to fully enclose and integrate into the floorplan. Without the waffle pod construction and just with the strip footing is this not a possibility? What further preparation would need to be done? So I guess what I'm asking is this, even though the full waffle pod construction is "engineering overkill" are there long term benefits to be had? Just trying to get a handle on all my options. Jo I leave you to fend for yourself, figure things out yourself. Terrence Malick Re: For TDL or any other engineery types. 19Jul 20, 2008 5:33 pm The roof loads are fully supported by the existing column foundations and the support offered by the house.
If I was to enclose it permanently I would use lightweight construction (not-brick) probably going for a "conservatory" style enclosure (all windows).....in which case it would be fine on a concrete slab as it would only need to hold the lightweight wall up which is bugger all in weight. As far as future owners go - who cares? - it's unlikely that this would impact on resale. I still wouldn't pay extra for a waffle pod in this part of the house - unnecessary and the substantial savings made could be better spent elsewhere or paying invested back into your mortgage. mmm....donuts Homer Simpson 1956- Links: Site Costs Ready Reckoner | H1 Addiction Medical Advice | Château TDL: The Backyard Re: For TDL or any other engineery types. 20Jul 20, 2008 5:47 pm Mmmm , Beginning to think I may follow Eager's lead on this and pull pin on the whole thing and revert to standard which is nothing out there at all.
I think they may still charge an arm and a leg to do it as the engineering stands. Still haven't got any indication of a price on that. Have to inform tomorrow, so a bit of thinking to do overnight. Just a bit worried about getting it done over handover. Jo I leave you to fend for yourself, figure things out yourself. Terrence Malick I recently went through a similar renovation and move scenario when updating our family home. We also swapped some rooms around and tackled a major… 2 9755 A question. Im in Queensland and building a new home. We managed to reach practical completion 6 weeks ago but we haven't heard any date for handover yet. Who should we… 0 5799 i had the my concreters concrete right up to the fence. I have pits all along my path, so the water tends to drain away from the house and into the pits. There's only one… 7 12717 |