If he can find the crack, he should patch it directly. Then, since you've gone to the biggest expense--excavating the wall--it makes sense to take further measures.

Tar (actually asphalt cutback of some sort) is merely dampproofing and is not used before any type of "blue skin" that I know of. Possibly he was referring to the Primer that is used before applying Blue Skin membrane. Where there is a special concern about water, some builders will also add a Delta style membrane after the Blue Skin.

Beside the membrane style "blue", there are several blue spray-on coatings. If your contractor is using any of these, I would add a Delta-style membrane as well, as the spray has a limited ability to creep to cover any new settlement cracks that may develop.

Backfilling with granular material is very desirable, as it allows groundwater to filter quickly down to the weepers. That your contractor understands that shows to me that he likely knows what he's doing.

Here is a link that might be useful: Code Blue

See the link to Delta in my previous post.

My engineer's advice on granular backfill is "whatever's the cheapest". In the Toronto area, this could be sand, recycled material or Granular "B" a mix of sand and small stones.

I'd keep the roofing tar on the roof and fill cracks with material designed for foundations.

plumberforhire
I'm sure you meant well. But the Forum instructions include this directive:
"* No advertising is allowed in any of the forums."

Posters can easilly contact you through the members page if you set it up to do so.

3/4 stone to backfill

I was specifically warned against using this by Egberts Engineering, Toronto, whom I consult with. The 3/4 stone drains, but by the same token, it allows cold air next to the foundation; it's as if the foundation wall is not below grade. In cold climates, this can lead to frost heave and foundation failure.

I will confirm this later, but it seems that my contractor will be using a peal and stick membrane that goes by the brand name Resisto

Here's the manufacturer's application video.

Note that under "hints" at Resisto's site, it says the ideal application temperature is between 10Ëto 25Ë C.

Here is a link that might be useful: Resisto