I'd replace the stack if it was a south-facing wall and in the summer. Did one last year and I got more of a tan than a week in Ibiza!!
We recommend uHeat for Underfloor Heating Systems, and The Wetroom Store for all things bathrooms and wetrooms. They provide discounts for forum members.
Welcome to the forum. Although you can post in any forum, the USA forum is here in case of local regs or laws
They do a support collar if your worried but i think you would be fine its how i would do it cast tee then black 110mm out the branch , no.way i would take the stack down . kop
Speaking from experience i would use the timersaver anything else wont look right Fernco no i wouldnt, 100mm will fit its measured internal just get the right collars a days work , changing the stack a weeks work a tower needed in poor weather no way £1000 at least you know it makes sense get the timesaver . kop
We recommend City Plumbing Supplies, BES, and Plumbing Superstore for all plumbing supplies.