Thanks for all past answers, they have all worked perfectly. This question is about a floor that slopes one and half inches in the middle. The house is 85 years old with approx. 3 1/2 wide planks for flooring. (Sorry about that weak description) I thought about jacking it up from below and putting sister joist on it and re doing the supports downstairs, but also though about strapping the floor to bring it up then laying down laminate flooring. If I strap it do I also need to put down plywood over it?
Answer:
If you were to jack it and re-do the support posts and beams, there should not be a need for strapping or plywood. You might not even need to lay in the plywood underlayment. The manufacturer of your laminated product will be very clear on this.
