I tried your method this afternoon. As soon as i started spraying they came out of the cracks and died. I must have knocked down 40-50. Its sure got to help. I'll see what it looks like in the morning.

Robert .... I think this is the stuff I use and it works great ...it causes a slight powder on the surface ..you cant see it ...but the spiders get it on their legs ... I'll check the name but almost sure that is it ... We have to get it at commercial suppliers ...m

Suspend® SC Liquid Insecticide - 1 pt.


CAUTION: PLEASE READ THE LABEL, THE LABEL IS THE LAW.

LABEL MSDS



DESCRIPTION: Suspend® SC Insecticide is a suspended concentrate containing Deltamethrin. Suspend is labeled to control a wide range of pests such as Ants, Firebrats, Gnats, Midges, Centipedes, Millipedes, Pantry Pests, Silverfish, Bees, Bedbugs, Carpet Beetles, Cockroaches, Crickets, Fleas, Flies, Hornets, Killer Bees, Lice, Mosquitoes, Pillbugs, Scorpions, Sowbugs, Spiders, Ticks, Yellowjackets, Wasps, Termites (localized control), and Carpenter Ants. Suspend® SC Insecticide is an prefered general purpose perimeter pesticide.

DIRECTIONS: Apply to exterior foundation and at all entry points such as windows, doors, etc.

Always read & follow the label directions!
Active Ingredient: Delatramethrin - 4.75%



1 pint makes up to 32 gallons of finished spray.

Everybody else's chemical suggestions are probably excellent, but the delivery, especially with a boat still in the lift cradle, might make a bit of a mess. Let alone what might get in your eyes. The foggers are cheap and available anywhere, and the delivery is easy and clean. Minutes after you treat an area you can see the results as the spiders will lower themselves on their webstring looking for some fresh air to die in. The fog must leave a residue that discourages them for a while because it will take a few months before I will see more spider droppings.