Repairing T-111 on a Chimney

Chimney Before Repair

If you have ever lived in a home with T-111 siding, you have probably experienced wood rot.  There are two leading causes of wood rot on T-111. The first is the paint drying out and absorbing moisture. The second is water finding an entrance due to a caulk joint failure. This occurs around windows, doors and at the seams.  The steps listed below are what to look for and how to repair it. This article is specific to a chimney repair but can be applied to other areas.  In this specific repair, we will be replacing the T-111 with a Hardie type panel and trim.
1. First, inspect the chimney.  More than likely the bottom of the T-111, where the panel meets the roof deck, will be suspect.  Poke around the perimeter with a screw driver to determine the extent of any damage.  At this stage, you can only find what you can see on the surface.
2. Remove the nails on the metal chimney cap with a flat pry bar.  Try not to damage the chimney cap as we will be reinstalling it later.
3. Remove the screws from the chimney cap flame arrester.  Remove the arrester and set aside.
4. Remove the chimney cap and set aside.
5. With your pry bar and hammer, remove the trim boards and discard.
6. Remove the nails in the T-111 with your hammer and nail puller.
7. Remove the T-111 and discard.
At this point you should be looking at the wood framing  and the chimney vent pipe.  Now you can inspect the framing and a portion of the roof decking for additional damage.  If you have wood framing, roof sheeting, or metal flashing that has been damaged due to water intrusion, now is the time to replace these items.
If you do not see damage you can start the rebuild process.
8. About an inch and a half up from the roof deck, apply a bead of roofing sealant to the metal flashing. 
9. Wrap the chimney framing with a quality house wrap.  Make sure the bottom edge is firmly adhered to the bead of roofing cement.  Secure the house wrap to the wood frame with button cap nails or staples. Make sure all the seams are sealed with tape designed for house wrap.
10.You are now ready to cut your siding and trim.  Once you have made your panel cuts, you are ready to secure it to the frame.  Put a thick bead of roofing cement approximately one inch up from the bottom of the panel.  This will form a water tight seal.  Paint all cut edges with primer or exterior paint.
11. Install the panels to the manufacturer’s specifications.
12. Paint the panels before you secure the trim.

Chimney After Repairs

13. Paint the trim boards before cutting them.  This makes the finished product look much nicer.
14. After the paint has dried, cut the trim boards to fit. Paint all cut edges to seal them.
15. Install the trim boards to the manufacturer’s specifications.
16. Caulk all seams and nail holes with an exterior sealant.
17. Re-install the chimney cap and arrester.  Apply sealant to the nail heads.
18. Touch up the paint and you are done!