Browse Forums Building A New House 1 Feb 08, 2015 7:22 pm I am paying extra to have chemical curing agent -Fosroc Concure A99 applied to my house slab on day of pour with my volume builder Simonds Homes as it may be poured in hot weather in March. I included this in my contract and also included in same clause to have form work left in place for 7 days minimum prior to removal and framing starting. Is this a consideration of owners when building or am I just paranoid? I hear of framing being commenced on green slabs. Concrete curing is essential in my reading especially if your pour is in the hotter weather to give the concrete a better start in life by assisting in water retention. Re: Concrete Slab curing. 2Feb 08, 2015 8:41 pm Its not a consideration for many . . . . but it is good practice. The Harder You Try - the Luckier You Get ! Web site http://www.anewhouse.com.au Informative, Amusing, and Opinionated Blog - Over 600 posts on all aspects of building a new house. Re: Concrete Slab curing. 3Feb 08, 2015 9:05 pm I suppose. It is just me wanting to be able to live in this new house for another 40years without too many issues. I am also going to the trouble of creating a 1 metre concrete apron with appropriate fall around the entire waffle pod slab at handover as well as keeping eye on the surrounding soil that needs to be graded away from slab during the entire construction period and for temporary downpipes to be fitted as soon as the roof goes on. I want the house to last longer than the 7 year guarantee period. Re: Concrete Slab curing. 4Feb 08, 2015 11:56 pm Hey Goody, how much is that costing you? We're also building with Simonds and told them we didn't want our slab going down in summer - if they didn't get it down before Christmas, they'd have to wait until April. Then we were told blah blah. But we're more than happy to wait until April. But I think they're going to get going in March ??? Re: Concrete Slab curing. 5Feb 09, 2015 1:36 am TomCat Hey Goody, how much is that costing you? We're also building with Simonds and told them we didn't want our slab going down in summer - if they didn't get it down before Christmas, they'd have to wait until April. Then we were told blah blah. But we're more than happy to wait until April. But I think they're going to get going in March ??? It was about $600 off the top of my head, I can check cost in contract tomorrow and post here if too different. My slab size is about 25 squares and single story. That Fosroc Concure A99 will also need to be removed after the 7 days too as it sometimes may not take other trades 100% but it will need to come off as I am doing about 75 sq m of 6mm vinyl floor planks in the living areas. That will require the slab surface to be levelled 100% with a levelling compound and ramped up at doorways meeting tiles and carpet and that is why the concur A99 will need to be removed to be able to take leveling compound. It is easiest to be removed by high pressure washer before the frame goes up. The removal has not been discussed with Simonds as yet. I will bring it up after curing compound applied. They will have to do it or I will do it with their approval. One way or the other it will need to be done. The formwork will also remain on for minimum of 7 days too. That also assists in water retention. Another thought is to get all PVC pipes (Storm and Sewer) joints in expanding and swivel by Stormplastics if you have highly reactive clay soil sites for your construction. That added about $1200 to the contract. I am paranoid about waffle pod slab, slab heave, pvc pipes leaking and slab failure. I am trying to do my best to avoid serious issues. I will be happy once it gets out of the ground to a high standard. Then the rest of the house should follow in a good to high standard I am hoping. I will be using Building Expert (On this forum) for a prepour inspection too to have an independant eye on slab preparations. Re: Concrete Slab curing. 6Feb 09, 2015 6:10 am Thanks. You might be interested in this thread: viewtopic.php?f=31&t=75222&p=1287381#p1287381 Re: Concrete Slab curing. 7Feb 09, 2015 1:18 pm TomCat Hey Goody, how much is that costing you? We're also building with Simonds and told them we didn't want our slab going down in summer - if they didn't get it down before Christmas, they'd have to wait until April. Then we were told blah blah. But we're more than happy to wait until April. But I think they're going to get going in March ??? I looked at contract, extra cost on my coin was $660.00 for application of curing agent and leaving form work on for 7 days. An extension of 7 days was also placed on construction period too. I wonder how long they planned to let concrete cure without any addition curing methods before the frame went up? Makes you wonder about good building practices of Volume builders. They only care that the house stays up for 7 years I believe. Re: Concrete Slab curing. 8Feb 09, 2015 4:54 pm On a side note. This morning I drove past a conventional stiffened beam raft slab for units being poured. It is about 30 degree day and sunny here where I am. An hour ago I came home to find concreters gone and form work all taken out and gone off site too. I doubt any chemical cure agent was applied. Definately no other curing methods like ponding of covering applied. I bet tomorrow the framers will turn up and start framing. Very poor building practice as far as sufficient slab cure goes and I am a lay person who has just read about such requirements. Does anybody really care about what they build these days? I am sure there are persons that do but lots that don't. Re: Concrete Slab curing. 9Feb 09, 2015 5:10 pm Is a pretty good practice. I repent not knowing about this earlier, when I did, it was too late and the slab form work all removed within the day. It rained continuously for 4 days after that though, so they couldn't start framing. That was some sort of fall back for me. When asked, the SS mentioned they added a curing agent. However, like you I am going to have Vinyl as well, and can't see any removal process started to have the slab perfectly levelled. I have some chips on the slab's surface as well, and I think they should fix it with a concreter before the vinyl goes in. Re: Concrete Slab curing. 11Feb 11, 2015 7:31 am TomCat Hey Goody, how much is that costing you? We're also building with Simonds and told them we didn't want our slab going down in summer - if they didn't get it down before Christmas, they'd have to wait until April. Then we were told blah blah. But we're more than happy to wait until April. But I think they're going to get going in March ??? I spoke to a tech with the concrete products supplier Alan McKenzie from Parchem. He said the high pressure washer wouldn't remove the curing compound Concur A99 sufficiently and suggested a process of hiring a double head walk behind concrete grinder for the process at the end of the seven days of curing and before frame commences. Grind then rinse off with water. Then slab will be right to take any after trades. It will be easiest to do this before frame for sure and difficult after frame. That is the way I intend to do it now. I just have to clear it with Simonds Homes unless they say they will do it. Re: Concrete Slab curing. 12Feb 11, 2015 7:58 am Plastic works a LOT better and considerably cheaper and the after effect is, well not a problem. If a high pressure wash worked then how would the curing agent stop the pressure developed by a slab outgassing moisture? Where you are coming from is where you are going to... Re: Concrete Slab curing. 13Feb 11, 2015 9:11 am onc_artisan Plastic works a LOT better and considerably cheaper and the after effect is, well not a problem. If a high pressure wash worked then how would the curing agent stop the pressure developed by a slab outgassing moisture? Thanks for the tip on plastic, you are right regarding cheaper and ease of removal as for the rest of what you are saying I don't have the knowledge to comment. Re: Concrete Slab curing. 14Feb 11, 2015 9:24 am .. and if anyone thinks the plastic is a waste then think of the energy and chemicals that will be used to make the curing agent that will either cause an issue and in the end will also become scrap, add to that the cntainer, the manufacture of the container, the transport of dangerous goods and what is in that stuff to make it worth $500 for 20 litres?. At least you can line the bottom of a veggie garden, flower garden or other water saving measure, will you have a drive way that needs a WPM waterproof membrane? Quick and easy is in itself something to be wary of. Where you are coming from is where you are going to... Re: Concrete Slab curing. 15Feb 11, 2015 12:25 pm onc_artisan .. and if anyone thinks the plastic is a waste then think of the energy and chemicals that will be used to make the curing agent that will either cause an issue and in the end will also become scrap, add to that the cntainer, the manufacture of the container, the transport of dangerous goods and what is in that stuff to make it worth $500 for 20 litres?. At least you can line the bottom of a veggie garden, flower garden or other water saving measure, will you have a drive way that needs a WPM waterproof membrane? Quick and easy is in itself something to be wary of. I am doing the drive after handover yes. I have got nothing against the plastic as a moisture retaining method at all. I will try to have my contract chemical cure($660.00 worth mind you) changed to use the builders plastic instead of the concure A99 and then I won't need to remove the chemical cure compound with a grinder. Thanks for your input. Re: Concrete Slab curing. 16Feb 11, 2015 12:29 pm If they try and absolve themselves from warranty tell them to refer to the BSofA and the last 25 years. Plastic is a WAAAY better option even having to weigh it down and if it blows off a bit then you know to recover... the curing agent can be incorrectly applied and you will be none the wiser Where you are coming from is where you are going to... Re: Concrete Slab curing. 17Feb 11, 2015 7:31 pm onc_artisan If they try and absolve themselves from warranty tell them to refer to the BSofA and the last 25 years. Plastic is a WAAAY better option even having to weigh it down and if it blows off a bit then you know to recover... the curing agent can be incorrectly applied and you will be none the wiser After being told of having to grind off I am going to ask for the plastic application. How can they say no as they will still charge me $660 but pay concreters a lot less to cover with builders plastic rather than spray with Concure A99. Then leave plastic and form work in place for 7 days minimum. Re: Concrete Slab curing. 18Feb 11, 2015 9:42 pm Forms on for one day (but many builders are forming up for the concrete so the forms can stay on for a good long while) and that will reduce breakouts on the edges. plastic should be the roll of a concerned individual:) roll it with the wind and a mate to laugh with and keep it close to the ground.. although paragliding can be fun, it is necessary for both participant to be ready and willing to fly. All the reasons that defy covering with plastic pail into insignificance to covering with plastic and a better outcome. Where you are coming from is where you are going to... The concreter will take and reuse. In my case I bought structural LVLs and scraped them back and used them as joists. 1 5118 yep, clearly mark where the infloor heating pipes are before drilling or nailing 1 6041 Building Standards; Getting It Right! is this for a residential dwelling or a shed? If its for a dwelling, its out of tolerance and a "mistakes happen" isnt a good enough excuse to just move on. 1 2394 |