Tarmac overlay and tac-coat /sealant query

[Mic]

Hi All

I am new to this forum and am looking for some advice following re-surfacing of my drive.

I week ago I had a section of my drive resurfaced. There was nothing particularly wrong with the existing drive however following some drainage work required a small section to be dug up I decided rather than have a small patch it would look better if I resurfaced a larger area.
The quote from the contractor stated the following (amongst other things): a
1. Apply a K1-40 tac-coat adhesive emulsion by mechanical sprayer to existing tarmacadam surface to bond new macadam to existing surface.
2. Vertically seal cut joints by applying a cold colas bitumen sealer

Although the finish of the drive looks ok (it’s still very new), the contractor has failed to carry out both the above points. I am particularly concerned that tac-coat (at least that’s what I think it was) was only applied to a very small area. This was poured randomly from a container. The rest of the drive was simply swept of debris and the new tarmac rolled over. My concern is that the new layer will not bond to the old layer and will in due course begin to separate either through frost penetrating the layers and/or traffic wear.
Also the vertical joint between the old and new drive has not been sealed. Please see pictures.

I have challenged the contractor and their response is as below:

“Tac-coat is not used to completely cover an existing drive-way before the new surface is laid. (it is a water-based substance and spreads easily across a surface). It depends on a few factors to how much is used; however, it was hot on the day your driveway was completed and this is one of the many reasons less may have been used. We can assure you that the new surface is fully bonded to the old surface.�

Finally, as result of the overlay the floor of the garage is level with the drive whereas previously there was around a 2cm step. Is this normal practice?

I would welcome any comments in order to decide how to progress these points with the Contractor.

Thanks

ps - apologies - I don't know how to load photos.

[Tony McC]

If the tack coat isn't essential, why did they include it in their quote?

If it is indeed stated in the quote and they failed to supply and install as stated, they are in breach of contract.

Tack coats are not always essential, but they can only make for a better quality finished surface. That's why they are almost *always* used with highway re-surfacing projects.

The bit about a tack coat somehow self-spreading because it is water-based is pure bollocks, as is the ambient temperature when the work was carried out.

[Mic]

Thanks for your comments Tony

Obviously there is nothing they can do now (short of ripping it up!) so based on your breach of contract suggestion I will offer to pay a reduced bill by £100-£200. No idea how much it would have cost them to cover approx 44sqm with tac coat.

ps - I am curious to know how the finish would be affected with/with out tac coat given that this is applied below the new layer?

[Tony McC]

I'd be looking for a price reduction of 5 times that. It's not just the cost of tack coat plus labour, it's the gamble you are now obliged to take because they are in breach of contract. You have not got the work for which you contracted, and for which you were asked to pay.

The most likely result from omitting a tack-coat is that the new wearing course separates and starts to come away from the underlying substrate. Many of the potholes we see on the highways are due to a failure to bond, ie: lack or faiulure of the tack-coat, as seen below...




There's no certainty that this *will* happen. You could get twenty years of trouble-free service, but that's not the point. There is a far greater risk that it *may* happen, and if it does, 100-200 quid is not going to come anywhere near the cost of remedial work.

The legal view would be that they are in breach of contract and therefore you could compel them to re-surface from scratch, to provide the surface using the materials they contracted to use, or to cover the costs of you bringing in another contractror to do the job as specified. That is a BIG lever to use against them. If it ever got as far as a court, they would not want to risk that outcome, and even a 'relaxed' magistrate on a good day would understand the the breach was worth far more than a couple of hundred quid.

[Mic]

thanks for your reply - really appreciate it.

[loudog]

What did they say about the cold joint sealer as that is just as important as the tack coat. They have talked a good game as in mechanical sprayer but I've been in the tarmac game for 40 years and for a small patch using a mechanical sprayer isn't something I would use as you can equally get it a good covering with a watering can and brush just as long as it's all covered. I'm with Tony, yes it could last 6-8 years even 15-20 but you are taking all the risk here.

[Mic]

Thanks for your comment.
I have written a lengthy letter to the contractor following all the feedback received from this forum. I have offered to pay half the original invoice in final settlement. I am hoping to hear back from them by end of next week. Will keep you informed.
ps - when I first raised my concerns to them - one of the directors/owners (whom I recognised as being on site on the day the work was done) came round and within minutes of me trying to explain he stormed off threatening to dig the place up!

[Tony McC]

If Mr Angry was to dig up the work, you would have a very, very strong case against the business.

Once building work is carried out at a property, even if the invoice isn;t paid, and money is owed for labour, plant, and materials, the law regards the work as being "vested" in the property and it would be regarded as criminal damage to attempt to remove said materials from the site.

Bloody annoying, I know, if you are the contractor faced with an awkward git of a client, but faced with such a situation, just about the worst thing you can do (other than clouting the awkward git of a client with the back of a spade) is to remove fixed materials from the site.

If there are any *unfixed* materials, such as packs of blocks/flags, loose sand and aggreagte, bags of cement, etc., they *can* be removed, as they haven't been built into the property, but anything laid, even if it isn't finished, is a no go.

So, if Mr Angry doe sturn up threatening to dig it all up, just cal the police - let them deal with him!

[Mic]

They agreed to my offer to halve the bill. I am happy with that.
Thanks to everyone's advice - appreciated. I have definitely learnt a few things about tarmacking!!

[Dave_L]

So you got your 44m2 driveway resurface at half the quoted cost? You've done well!