Tectum decking repair/replacement


I live in a 1958 home with tectum panel decking and some sort of roll roof on top of it. The panels of tectum that are inside are in perfect condition. However, many areas around the house where the roof “overhands” are badly damaged probably from water. Is there any way to solve this problem from the underside? Like with replacement tectum? Or do we have to tear off the top to get to the damaged areas then replace the roof over the decking?

Sorry if I sound clueless–it has taken us 6 months to even learn that it’s called tectum panels! I have spoken with roughly 30 roofers, contractors and the like and no one has experience or any way to help. We live in rural southeast Missouri so not as many resources.

Thanks for any advice/info!

The roof must be removed to replace the tectum. It will not be cheap.

I was afraid of that…what would you call not cheap. For about 3500 square feet. Are we talking 10k expensive or like 30k expensive?

Closer to $30k than $20k.

Goodness. Is that for tectum alone or the whole job and replacing the roll roofing on top once the tectum decking is replaced?

It could very well be >$30k also.

It all depends on the scope of work involved.

A repair if possible would be less expensive.

Im afraid you still havent found a roofer that knows what hes looking at and how to fix it.

That is not tectrum.
That is called homasote.
Id strongly advise that you dont use anybody that cant identify this product because he surely will not know what to do.
Even if you idenify the product for them…
Keep looking for a qualified roofing contractor
That instantly knows what the product is
Without you telling them.
Homasote comes in different shapes and sizes.