Ants in roof ? Damage from humidity or living organism ?

[Charles H.]

Hello BP Rehabbers!

I spotted a house for sale for months and months in a beautiful area in hilton head island, SC. The house has a cathedral celling design, which is unique to the community so ... it gives me some interest to work on this house.

Now, while looking at it, it has been empty for 2-3 years, apparently with windows opened. The inside is not that bad actually, i didn't find many signs of mold, except the floor in the main room that warped. It looks like some kind of engineering or laminate floor, on top of a slab so i am not worried.

What i wonder is the roof which looks good from inside, except at 2 locations.

Attached is a picture of one of the location, where i spotted a highway of ants. Pen/thumb to show scale.

Roof was never changed. 1990. I understand it might be tricky, but would replacing the roof be the main thing to do, or do you suspect some other costs seeing the damage/ants?

Any idea on the cost (just an idea) looking at the shape of the roof ? Doesn't seem like a complex roof. House is 3000 sq ft.

Also I didn't find the outside air conditioning units...wtf? Not even a piping, except 2 pipes going into the ground outside, but i would be highly suspicious that it's geothermal here in SC....

Thanks all.