# Cut top and sole plates when running HVAC ducts?



## toddmanqa (Oct 31, 2008)

I am in the planning stage of putting in a Heat Recovery Ventilator (HRV) in a two-story colonial with basement.

I have central air located in the basement with a full set of supply and return ducts in every room (except none in the unfinished basement, and no return ducts in the two bathrooms or the kitchen). 

I am planning on running the HRV dirty-air intakes from the two bathrooms and the kitchen, and then direct the incoming fresh-air into the three bedrooms on the second floor.

This steup was recommended by American Aldes ventilation, a manufacturer of HRVs:

http://www.americanaldes.com/Editable/Insert-library_files/Install HRV-ERV units.pdf

In regards to running the new ducts vertically, does anyone know the code/rules in regards to cutting sole and top plates? 

Do the rules change if it is a load-bearing wall?

Thanks!


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## tpolk (Nov 7, 2009)

I always thought return air from baths and kithens was not so good do to odors and moisture


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## beenthere (Oct 11, 2008)

tpolk said:


> I always thought return air from baths and kithens was not so good do to odors and moisture


The air won't be mixed with the fresh air.


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## tpolk (Nov 7, 2009)

cutting out wall plates is never a good idea unless you have a way to eliminate their desire to hinge out on the horizontal


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## toddmanqa (Oct 31, 2008)

*Found an answer*

R602.6.1 Drilling and notching of top plate. When piping or ductwork is placed in or partly in an exterior wall or interior load-bearing wall necessitating cutting, drilling or notching of the top plate by more than 50% of its width, a galvanized metal tie of not less than 0.054” thick (1.37 mm) (16ga) and 1.5” (38 mm) wide shall be fastened to each plate across and to each side of the opening with not less than eight 16d nails at each side or equivalent. See Figure R602.6.1.

Exception: When the entire side of the wall with the notch or cut is covered by wood structural panel sheathing.

And here are some nifty graphics (see page 9) of this document:

http://www.strongtie.com/ftp/fliers/F-REPRPROTECT09.pdf

It appears you CAN do it--just can't do it for more than two consecutive stud bays.


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