I have added pictures of the crawl space to illustrate the current conditions.
Add joist to exisiting floor.
If the attic joists are not adequate one way to strengthen the floor for live loads is to sister the old joists.
Then attach the sister joist using three 16d common nails driven every 16 in.
Nail the new joist to the existing joist with two rows of 10d to 16d nails spaced 6 in.
Gwi 1498683 my plan is to add 2x8 joist in between the existing joist for a total of 4 additional joist.
Purchase the type of lumber that matches the width of the existing joist.
Sistering is the process of adding a new joist next to each existing joist.
In situations when sistering damaged floor joists with lumber of similar dimensions it can be easy to notch and slide the sister board into place.
Take some extra time and jack the damaged area up so that the new lumber doesn t need to be.
So if you have open access to your floor joists now you can add the comfort and efficiency of radiant floor heat to your home.
Even if your joists already have a row of bridging at the center of the span adding a row on each side of the existing bridging will stiffen the floor.
Use a tape measure to measure the length width and height of your existing floor joist.
General area of concern.
Of the existing joist.
Find a new floor joist with these exact same dimensions.
If your floor joist is an i joist for example buy an i joist.
Most new construction uses 2 by 8 lumber for joists although 2 by 6.
The best way to limit annoying flex in a floor is to make sure that joists are sized correctly before a house or addition is built.
Use a sledgehammer or a pry bar to force the bottom of the new joist along the mudsill and center support beam of the floor system or the opposite mudsill on short spans until it s flat against the existing joist.
Find a replacement joist that is the same size as your floor joist.
Make sure you also buy the same type of joist.
Measure the width and length of the existing joist.
When the sagging joists are level apply a generous bead of construction adhesive to the existing joist.
This add on has joist running perpendicular to the rest of the house.
The retroheat system can be installed to heat tile hardwood laminates.
Driving 16d common nails in old hard wood is difficult.
Bridging or x bracing allows joists to share weight.
Building codes specify the minimum joist depth and spacing typically 12 or 16 inches on center for spans up to 20 feet but those requirements are intended to prevent plaster ceilings from cracking not to.
However doing this does not fix the slant that the floor has taken since the old joists got damaged.
As a footstep falls on one joist some of the force is transferred to neighboring joists.
Retroheat radiant floor heating system.