Browse Forums Owner Builder Forum 1 Dec 21, 2008 12:48 pm Hi everybody
We are planning to put our slab down at the end of Jan. At the moment I am trying to educate myself as much as possible on the whole process, I don't want to miss something. Any feedback of what we should look for during the job would be greatly appreciated. I don't want the concretors to do something wrong thinking that we know nothing. Thanking everyone in advance Nina "The fearless are merely fearless. People who act in spite of their fear are truly brave" - James A. LaFond-Lewis Re: Things to look out for when doing the slab 2Dec 21, 2008 1:50 pm I take it by your footnote you are doing this as an owner builder and are taking the responsibility of the builder.
So you need to take more precaution. As an owner builder I would be doing the following. 1. Insuree that all the sewerage and wast pipes have all been installed and are in the correct location. (Pre Slab) Best to use string lines on survayours pegs and make sure centre to centre distances are as per the plan. 2. At slab stage. Make sure you know what finished height you want ( if not stated on the plans). Then work out the height of your rebates etc. This should be considered with you final levels for concrete paying etc. 3. Make sure that the boxing when complete is correct as per the plan, and that all edges are true (straight). - make sure the slab is in the correct position. Rember if you block in on a slope you have to measure the setback while the tape is level. You cant put measuring tape on the ground and measure. 4. On day off pour if you dont have a fixed price (for slab and concrete) i would be counting trucks etc. Also I would be measurin the trench depths and re measure how much concrete it should take. Then add 10%. It shouldnt be to far off. Note there are also other things to check but that is the role of the inspector. rememeber the inspector doesnt check quality of a house just the safety aspect of providing solid construction. Doesnt care if you slab is out of square. Keep that in mind. Also I am from Vic so excuse me if any of the above dont really relate to you. Re: Things to look out for when doing the slab 3Dec 24, 2008 3:53 pm hi nina, borgs advice is very appropriate, & seeing u r a WA o/ber, i feel a lot safer making comment, cos our footings & slabs r done quite different to many in eastern states - we rarely use waffle pads like they do, i guess if ur on the perth coastal plain which most likely mean urs will be a sand pad? firstly the structure of ur footings/slab will depend on the type of construction u r using - is ur build standard b/veneer, reverse b/v, frame, or d/brick - thats my 1st question?secondly do u have ur profiles in? once i know this, i'd be in a better position to perhaps give some assistance.
cheers tony Re: Things to look out for when doing the slab 4Jan 02, 2009 4:00 pm Hi Borg and T&V
Thank you both for your input above. T&V, our land is pure sand, the house is going to be double brick. We have our engineer's specifications plan and I think I can now make sense of most of the information on it. My question was more to do with us supervising the job on the day. I know each contractor has their own way of doing things, but I just don't want to miss something important. Nina "The fearless are merely fearless. People who act in spite of their fear are truly brave" - James A. LaFond-Lewis Re: Things to look out for when doing the slab 5Jan 02, 2009 6:05 pm Hi Nina,
Quote: My question was more to do with us supervising the job on the day. I know each contractor has their own way of doing things, but I just don't want to miss something important. You're not saying what sort of arrangement you have with the concretors, but in general it's best to leave them alone to do their job, after making sure that the drainage rough-ins are in the right position, etc, as per Borg's point 1. Insist that the plastic membrane overlaps're taped and that there're no holes in it. Make sure they use barchairs to hold up refo. It's a good idea to make a copy of the reinforcement and concrete delivery manifests for your records. Discuss the size and shape of shower hob(s) and any blockings with concretors, before they start, to make sure that they've got them right. Find and point to them a suitable place for dumping the left-over concrete and washout, so it can be easily broken and removed. Discuss slab curing method and ask if there's any curing additive in the mix, if they'll spray curing oil, etc, and watch the weather forecast for the day. If water ponding/spraying is recommended, be ready to start shortly after slab's finished and make sure that it's not too hot - a temperature difference greater than 5 degs between water and concrete is unhealthy for the slab. Good Luck Chris My father rode a camel, I drive a car, my son flies in a jetliner, his son will ride a camel.Saudi saying Re: Things to look out for when doing the slab 6Jan 05, 2009 12:57 am Hi Nina, again Chris's above advice is good, just a few thought from me - who's going to do the profiles? once these r in check for exact squareness, its very important that all sectors of the slab & slab overall is square otherwise the "non-square" problems follows u all thru the build!
re shower "hob" i'd really suggest u set any shower recess below slab level - slab level showers so often cause problems in years to come with moisture thru adjoining walls. if u drop the recess, check its against the wall if so designed, also measure to all other bathroom walls to check exact location. re unused cement - have somewhere framed up to "usefully" put any left over concrete ie path in backyard, mow strip around a shed, flower bed edges - anything is better than wasting it!! finally, check all the exact location of any underslab power, water& drainage pipes, if u have any island benches with either power, water or kitchen waste drainage requirements make sure these r provided for - i've seen more than one slab have its structural integrity damaged by having these "cut" into the slab becos they were forgotten about! cheers Tony Re: Things to look out for when doing the slab 7Jan 06, 2009 11:18 am T&V check all the exact location of any underslab power, water& drainage pipes, if u have any island benches with either power, water or kitchen waste drainage requirements make sure these r provided for - i've seen more than one slab have its structural integrity damaged by having these "cut" into the slab becos they were forgotten about! cheers Tony Hi Tony, Our builder was disorganised enough to lay the slab with plumbing in wrong place based on old cupboard drawings. They had to cut new channels. What should I be looking for that would indicate that the slab is failing? When is this likely to happen? Re: Things to look out for when doing the slab 9Jan 06, 2009 3:59 pm borg Slab will fail if it starts to crack significantly. This will most likely happen if you cut the steel mesh (reo). How deep and how long did they cut. Up to 2 metres. Partly through mesh and others surface channels. Done about 5 months ago. Only fine cracks developing from the point where it was cut - via stress risers? Re: Things to look out for when doing the slab 10Jan 12, 2009 12:23 am Hi Dymo69, no i dont think u'll have any trouble, i've just had an engineer friend of mine look at some fine surface cracks that have occured on my slab while i was away on holidays and i also asked about the situation u outlined.
he said fine cracks were shrinkage cracks due to hotter days- when we looked closely we found all the cracks are in the biggest open areas where the floor is exposed longest to the sun family room, lounge room & garage. there were no cracks in passages, bathrooms, laundry, office, smaller bedrooms or pantry - walls closer together & keep sun off the floor in these areas. b4 i went away i was keeping slab moist, & delayed putting roof on to allow the internal bricks to completely dry after our wetest ever Nov so that i wouldn't have trouble with render lifting. i've never had shrinkage cracks occur in a slab b4, but engineer says there are more slabs with them than without these days! it appears to me that some of this may happen becos of the extra chemical curing agents they put in these days, don't get me wrong i also recon that todays slabs are very, very strong & far better than old days, but IMO part of the trade off for strength is these surface cracks that again IMO probably happen becos the surface material is a lighter density than main core - ie trowelling machine brings sand, finer aggregate & water to the surface. my slabs has been down for 5 months & the engineer said that major structural cracks usually occur soon after the slab is poured, open up very quickly & get relatively wide very quickly, u can put a coin in them! if these do happen, today there are a lot of ways to stabilise problems with pins & special glues!!! so if ur cracks r fine cracks they could well still be shrinkage... cheers tony Re: Things to look out for when doing the slab 11Jan 12, 2009 9:15 am Quote: he said fine cracks were shrinkage cracks due to hotter days- when we looked closely we found all the cracks are in the biggest open areas where the floor is exposed longest to the sun family room Our slab's been baking in this blasted heatwave for 3 weeks. It developed quite a few cracks in spite of the thorough wetting in the first 10 days, some of them running all the way across, but they all seem to be surface. I'll have someone to come and have a look at it. Chris My father rode a camel, I drive a car, my son flies in a jetliner, his son will ride a camel.Saudi saying The DIY project can be broken into two major steps. Planning and Design and Construction. Both of these steps are as important as one another to ensure you give… 0 5149 Hi group, have some damage to the door frame and skirting board. It's a side door to the laundry area. Only has a security door. I had a termite inspection (note drill… 0 5050 0 1967 |