Sub base material and depth of tarmac - Query re depths and types.

[Drax]

Hi

I need advice on this job in progress.

I did a full specification, and got a quote for it. I accepted it relative to my spec. and sent back the acceptance with my spec. and an agreed minor change.

1. The contractor turned up and I had to get him to excavate more depth. He then delivered base material I don't recognize - he said "it off the road, is DTp1, and is better than DTp1".

It looks like tarmac, pebbles and stone mashed up. Will it be okay?

2. Having placed the 150mm kerbs, he built up and compacted the sub base, but only left about 50 mm between the top surface and the top of the edgings kerbs.

I don't see how he can lay the first 60 mm tarmac course and then the 30 mm wearing course.

I understood these thicknesses to be AFTER compaction not before. So how does he manage that when he needs nearer 100 mm.

Am I correct?

I took the specification for the tarmac, base and kerbs etc. off "Paving Expert" (plus my own detail layout drawing).


As you can tell, I am not a little unconcerned - the good point is that it is not yet tarmaced and I have not paid anything.

Advice is very welcome, please.

[Dave L]

Can you post up a picture of these areas for concern?

[Drax]

Hi,

I have a whole sequence of pics. which include a metric rule for dimensions.

But, I can't find out how to post them - give me a clue.

Drax

[Stuarty]

To post pics, i usually use ImageShack.us. Click Browse, find the photo and click it. Then click Host It, wait a wee while so it has time to upload then u get a list of what to use. The first format is fine, just paste into this

and done.

[flowjoe]

Oi ! you can`t just go posting you national flag like that, you might offend somebody, and while your at it remove that veil so i can see your face.

:p

Is it me ?



Edited By flowjoe on 1160877526

[Dave_L]

PM sent to Drax

[Dave_L]

Looking at the image - the surface - it looks like 20mm base course?

The measure shows 55mm below top of PCC edger.

Is it a sealed type surface or is it loose?

"Off the road, better than type1?" Is he trying to 'sell' you road planings I wonder?

So has he laid & compacted type1 stone beneath this surface we see, then laid this stuff on top?

Oh and what is the proposed use of this new construction?

Sorry for all the questions!

[bobbi o]

looks like road planings,which is fine for a sub-base,looks good quality and has compacted well.

looks like 55mm to the top of the flat top kerb. i would guess the contractor is hoping to get away with laying a single layer of wearing course.which would be fine if thats what your paying for.

50mm is not deep enough to lay it in two layers,so if your paying for 90mm he might be hoping your stupid and trying to pull a fast one.

[Dave_L]

i would guess the contractor is hoping to get away with laying a single layer of wearing course.which would be fine if thats what your paying for.

Which will be fine if it is just a residential driveway and follows to your spec and their quotation........

[Drax]

Hi,

The only material laid so far is compacted sub base described by him as dry stone base material.

The specification included in his quote has a 60 mm tarmac base on top of that then a 30 mm wearing surface.

I just dont see how.

The other pics show on location with only 10mm height for this 90 mm requirment.

Oh, and he wants to allow a 6 mm lip all round the edgings so that reduces the available height for the tarmac by another 6 mm.

It looks like must express my concerns in writing tomorrow.

Drax

[Dave_L]

Sounds like the best plan of action, Don.

60mm base and 30mm surface is a good construction. Nothing wrong there but I concur with your concerns with the levels! It just doesn't add up!

Unless he's gonna scrape it back tommorrow with a machine, then re-compact it?

6mm lip around the edgers? Sounds odd - we usually (with flat tops) surface to the top of the edger, gives a nice edge and helps with drainage when the levels allow.

[bobhughes]

6mm = ¼ inch. Pretty accurate for tarmac??

[Dave_L]

6mm = ¼ inch. Pretty accurate for tarmac??

lol - hadn't picked up on that! Accurate to the stone size of 6mm surface course!

I'd like to see the finished surface! I don't think anyone could lay that accurately.