Access to my new double garage slab - Help required please !

[msh paving]

i hope you have not paid him for doing it, two layers is a total bodge up, that's my opinon ,if you asked for a float finish and he would not do it alarm bell would ring as to weather he was capable of doing the job, MSH

[DNgroundworks]

Mixing in a belle mixer? I can buy concrete in volumes as small as a cube from a mini mix company, and the two layers...as MSH has said is a complete bodge.

Have you let the garage company know of this?

[dig dug dan]

that picture was not the finished job was it?

Anything over 1 cubic m, and its not cost effective to mix by hand
Mark is right. That should have been poured in one hit.

[GB_Groundworks]

OMG are people actually our there charging for work like that?

you can't pour a reinforced slab like that in multiple small pours it will have no strength what so ever especially with a rough 5/6 to one mix in a mixer, should have been readymix from a wagon c35 one pour

if you are going to have a construction joint in the horizontal plane it needs to be full cleaned, scabbled and acid washed before topping off otherwise a good construction joint will not be achieved.


like rock said needed tamping, bull floating them brush or power flaoting and a radius putting on the entrance portion.

you need to send your "landscape" gardener guy over here to read the main site and stop bodging people garage slabs up

as for the ramp, just use the excess ballast and let the pavers sort it when they come, get 3 quotes and look at their previous work hopefully you will get a contractor who knows what hes doping this time.

i see another massive problem as well, your gardener has excavated into the bank and left a large 1.2-1,6m unsupported vertical earth wall?

is your intention that the precast garage supports this?

as it'll need to be ripped out and done properly with a designed slab with L bars coming up off prober reinforcing steel 10mm 0r 12mm mesh them 200-300mm thick concrete wall with a layer a A393 10mm mesh in it to retain that amount of earth, plus drainage and water proofing

any free edge of a concrete slab should have teh corner radiussed to prevent spalling and cracking






Edited By GB_Groundworks on 1393351993

[atone13]

Well the paviour came this afternoon and couldn't have been more obliging. He agreed to build the ramp and said he would raise it's edge so that water was directed down the drive and not off to the left (in the photographs), also he will build me a step so that I can access the personal door that is to be positioned down the left hand side of the garage and which will also be a foot above the ground. He asked what size ready mixed concrete lorry was used, and when I told him a Belle MiniMixer had been employed he was amazed but I didn't go into any other details.
The worst part of the story about the bank behind the garage is that when the landscape concreter finished the formwork for the garage base and realised the volume that had to be filled at the 1 foot end, he started under-cutting the bank by digging out its sandy soil which he used as a base layer. When I remonstrated with him that he would bring the bank down he said not to worry as there were plenty of roots holding it up though he did then stop the undercutting. During the course of the remainder of the fill there were several minor landslips on the bank which he was quick to point out had missed the garage base.
He had already asked for more than 50% of the estimated cost on account. I am a 71 year old pensioner and did not feel that I could refuse his demand for the balance when he had finished. He assured me that my paviour would have no problem with the ramp and he said he would leave me the unused ballast if I wanted to concrete it myself.
Until the paviour came today I thought I may have to cancel the purchase of the garage even though I had paid a 25% deposit so I haven't related the tale of woe to the garage manufacturers as yet.

[lutonlagerlout]

^^
as has been said a belle mixer for that size of pour is crazy
putting mud under slabs is wrong
a day joint horizontally in the slab?
I feel for you atone
this is a base we did for an oak garage






not saying its perfect but the pour was done in 1 hit with C30 concrete
LLL

[atone13]

That was all I wanted, a garage base next to my house, two or three inches above the ground, with a ramp so I can drive in.
You know I am having nightmares about this access, the only relief is when I get up in the morning and go and look at it and find it is only a foot high ! Anyway I'm confident that the paviour will build me a decent ramp.
Much to the Landscape Concreter's protests that it was unnecessary I did get him to put some steel mesh in the base albeit only 3 pieces each 12'x8' in a 17'x20'9" base.I asked for it to be laid to within 40mm of the edges but he insisted you only need it in the middle, did not wire the
Mesh sheets together and did not stand them on chairs,
instead he placed them between the Friday layer and the Sunday layer . Also I got him to put a Damp-proof membrane in despite his protestations, though I confess that neither of us knew what we were going to do with the exposed membrane if the formwork was removed. He could only suggest that I kept the formwork on and pointed out that he had used tanalised wood. The only suggestion I could find on the internet was to replace it with a brick skin. On the 1 Foot side I have pondered replacing it with a 1 ft high Concrete gravel board, he suggested that I could hold them in with angle-iron fence posts cut down. Any suggestions? At least the ramp will cover it on the front side.

[michaelthegardener]

to be honest I cant help thinking that it wont take the weight of the garage for all that long ...... but what do I know

[atone13]

The only saving grace is that before the base was laid there was a very well hard-cored gravel drive that had been where the base now stands for at least 30 years. The landscaper has not excavated any or substantially none of that hardcore. If he had the base would not be standing a foot proud of the ground. I suspect that that foundation may save me from any major disasters. The previous owner hard-cored the drive to withstand heavy lorries and none have ever damaged it thus far. If I thought otherwise I would probably slit my wrists - just kidding !

[GB_Groundworks]

Steel rebar needs an overlap 40 times its diameter for 6mm a192 is basically two squares overlapped giving 400mm overlap and be tied together and position in the bottom 50mm for strength or the top 50mm to prevent plastic cracking.

I think the chuckle brothers could have done a better job than that.

You are going to have to get someone who knows wgat they are doing to batter the banking back to 45 degree or cut steps in it or build a proper engineered retaining structure before your garage comes.

As once it's in and that bank goes be lot harder to rectify and might crack the concrete panels on your garage.

The membrane stops acids in the ground attacking the concrete and stops the loss of water out the concrete so you get a consistent strong slap that you can work.



Edited By GB_Groundworks on 1393397968

[dig dug dan]

what did he use the digger for if he did not dig into the exisiting drive??

[atone13]

The bank behind the site for the base was stepped. He used the digger to remove the steps mainly (I thought he was going to make new steps to retain the bank). He also used the digger to scrape away the gravel surface but when he came to the hardcore I suspect he found it too hard going as the digger only had a small and large bucket and no pick. He made no tests of the back to front level or right to left level of the site except by eye. He firstly constructed the formwork for the 8'x16' shed base seen in the right of the photos and levelled that at about 4" above the ground. Then he laid that base. The following day the digger was returned to the hire company and he proceeded to construct the formwork for the much larger garage which was 17' wide x 20' 9" long and I think he was genuinely surprised to find the far end coming out with a depth of 1'. I remonstrated with him that he had not levelled the site left to right and that he had let the digger go prematurely, but he turned a deaf ear and feverishly started undercutting the bank to start filling the base with it's sandy soil.

[Tony McC]

Referring to those bowed and buckling planks as 'formwork' is giving this cowboy far too much credit!

Normally, we pick at bits and pieces that have gone wrong on these sort of projects. I'm struggling to see anything at all that is right with this job.

[DNgroundworks]

Such a shame. How he could look you in the eye and take your money.......i hope you get it sorted.

Id honestly get a rep out from the garage company and point out all the concerns raised in this thread, you never know, you might get a proper foundation for your new garage and a decent arrangement for the now unstable banking, id definatley be asking the question.

Where do you live atone?

They did advise you to use this tool didnt they?

[lutonlagerlout]

sadly atone its like he has thrown the rule book out of the window and done everything the wrong way
on the plus side the concrete looks a strong mix and he has DPM which may just save it

unforgivable not setting out levels in the first place IMHO
LLL