There's absolutely no way to guess without further information.

It might cost less than 10 cents to DIY replace a missing roofing screw or nail, or millions of dollars to replace a roofing membrane on a stadium when the a4 sized leaky patch can't be patched because the whole system is stuffed / at end of serviceable life.

TBH get some contractors round and get a few quotes. only real way you will get an accurate idea of the costs

pih: Since nobody has given you any indicative costs, I'll chip in with my experience. We got a 3 bedroom tile roof repaired (half a dozen broken tiles on around 90sqm), primed and painted with two top coats for about $3500+GST, plus a repair and paint to our corrugated double garage which was an additional $500+GST, or about $4600 all up including GST. This included a 2 year leak guarantee and a 10 year coating guarantee.

I felt for the amount of work involved, that was good value.

EDIT: I'll add that the others are right, costs can vary wildly. Get a few quotes.

Depends where it is too. You may pay more in Auckland for example.

Jase2985:

TBH get some contractors round and get a few quotes. only real way you will get an accurate idea of the costs

neb:

Jase2985:

TBH get some contractors round and get a few quotes. only real way you will get an accurate idea of the costs

 

 

If it's "A4 size" it may be a squirt of silicone from a $5 cartridge, I doubt a contractor would be interested. The OP should post a photo of the problem to allow us to provide better advice.

Jase2985: maybe acceptable for "Casa de Cowboy" but an A4 area is an awfully big area to try and cover with silicone and still have it look nice.

neb:

Jase2985: maybe acceptable for "Casa de Cowboy" but an A4 area is an awfully big area to try and cover with silicone and still have it look nice.

See @Fred99's post, if it's a missing roofing screw causing a bit of rust then silicone or a butynol patch under a new fastener may be all that's needed. Since we have no idea what the problem is, it could be anything.

indeed so calling a roofer to look and quote isnt a silly idea either.

we have no ideas as the post is lacking information so each guess is as good as the others