How Many Holes In Blocking? - Roofing/Siding - DIY Home Improvement | DIYChatroom

Go Back   DIY Chatroom Home Improvement Forum > Home Improvement > Roofing/Siding


Thread Tools Display Modes
Old 12-31-2012, 03:08 PM   #1
Join Date: Dec 2012
Posts: 1
Rewards Points: 10

How many holes in blocking?

I'm adding 2x6 blocking to an existing shop. The trusses are 24" O.C. I'm drilling three 2' holes in each block. My question is: Do I need to drill every block to get enough ventalation (I know there needs to be roof vents.) or could I get by with say every other one?


Patrick Allen is offline   Reply With Quote
Old 12-31-2012, 05:19 PM   #2
Exterior Construction
Windows on Wash's Avatar
Join Date: Aug 2011
Location: Washington DC Metro Area (VA, MD, DC)
Posts: 10,171
Rewards Points: 16

How many holes in blocking?

It is best to vent each one.

How much do you condition the space.

I would rather see 1 - 2" hole per block than 2 - 2" every other one.


Windows on Wash is offline   Reply With Quote
Old 12-31-2012, 10:56 PM   #3
Registered User
Join Date: Mar 2009
Posts: 10,825
Rewards Points: 3,716

How many holes in blocking?

Depends on how much ventilation you want. With an 18NFVA ridge vent, you need 9NFVA per side of building per foot for balanced system. 2' block is 18"NFVA or 2" circle with screen is about 3"NFVA X 3 = 9NFVA, per foot----- so 6- 2" per block for 1/150, if using a vapor retarder (faced) insulation, 1/2 of that (3-2") for 1/300.
You did say shop...

If any ads are present below my answer or words underlined/colored, I do not condone/support/use the product or services listed/linked to, they are there without my consent.
WELCOME to the forums, if I forgot to say it!
Gary in WA is offline   Reply With Quote

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off

Similar Threads
Thread Thread Starter Forum Replies Last Post
Need help caulking and filling nail holes in my trim hadees Painting 13 11-25-2012 11:32 PM
Patching vinyl siding to "repair" small holes tomseeley Building & Construction 3 06-05-2011 10:12 AM
Holes in yard under tree - what is it? Leah Frances Pest Control 13 05-11-2011 08:22 PM
Holes in flange dont match holes in toilet! ljenkins Plumbing 2 02-06-2010 08:17 AM
Drilling Multiple Holes in Studs rjschwar Building & Construction 6 01-27-2010 02:05 PM

Top of Page | View New Posts