Forums | Home Repair | Home Improvement | Painting | Interior Decorating | Remodeling | Landscaping


Go Back   DIY Chatroom Home Improvement Forum > Home Improvement > Building & Construction

CLICK HERE AND JOIN OUR COMMUNITY TODAY...IT'S FREE!

Reply
 
Thread Tools Search this Thread Display Modes
Old 09-16-2010, 12:54 PM   #1
Newbie
 
Join Date: Sep 2010
Location: Okanagan Valley - British Columbia
Posts: 3
Share |
Default

flashing posts protruding thru a wall cap


we are designing/building an exterior (both sides) wall enclosing a exterior deck space with 4x4 wood posts extending 2' above the wall cap to support a pergola - i'm looking for a good solution to flash where the posts come thru the wall cap

Last edited by byronkw; 09-16-2010 at 01:31 PM. Reason: clarification
byronkw is offline   Reply With Quote
Old 09-16-2010, 01:09 PM   #2
Chicago, IL
 
Michael Thomas's Avatar
 
Join Date: Jan 2008
Location: Chicago, IL
Posts: 1,037
Default

flashing posts protruding thru a wall cap


Can you post links to 1) a wide angle view of the (parapet?) walls with the cap penetrations and 2) a close up of a post penetrating a cap?
__________________
Home Inspections, Infrared (Thermal Imaging) Leak Identification and Inspection Services, Roof, Attic, Building, Basement and Foundation Moisture Intrusion and Water Leak Inspections, Troubled Building Consultations - Serving Chicago and Suburbs
To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
Michael Thomas is offline   Reply With Quote
The Following User Says Thank You to Michael Thomas For This Useful Post:
byronkw (09-16-2010)
Old 09-16-2010, 01:36 PM   #3
Newbie
 
Join Date: Sep 2010
Location: Okanagan Valley - British Columbia
Posts: 3
Default

flashing posts protruding thru a wall cap


my apologies - i should have made clear that i am just starting contruction and am looking for a solution before i get too far ahead of myself
byronkw is offline   Reply With Quote
Old 09-17-2010, 11:25 AM   #4
Chicago, IL
 
Michael Thomas's Avatar
 
Join Date: Jan 2008
Location: Chicago, IL
Posts: 1,037
Default

flashing posts protruding thru a wall cap


In my experience it is extremely difficult to provide a durably watertight seal at the penetration of a roof membrane or wall cap by any type of wooden structural member, for example because the wood will absorb moisture, it will expand and contract both seasonally and shorter term at a difference rate as surrounding materials, it's difficult to provide a durable sealant bond to a weathering wood surface, and for many other similar reasons.

It other words, this type of penetration is an inherently Bad Idea.
__________________
Home Inspections, Infrared (Thermal Imaging) Leak Identification and Inspection Services, Roof, Attic, Building, Basement and Foundation Moisture Intrusion and Water Leak Inspections, Troubled Building Consultations - Serving Chicago and Suburbs
To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
Michael Thomas is offline   Reply With Quote
The Following User Says Thank You to Michael Thomas For This Useful Post:
byronkw (09-17-2010)
Old 09-17-2010, 12:51 PM   #5
Newbie
 
Join Date: Sep 2010
Location: Okanagan Valley - British Columbia
Posts: 3
Default

flashing posts protruding thru a wall cap


your comments mirror my own concerns - and the only system i thought might (?) work would be to countersink a flashing into the posts just above the top of the wall. of course that flashing / post intersection would be subject to all of the forces you describe too...

the follow-up question would be what mechanism would you suggest to suspend / support the pergola above the wall? use steel posts thru the cap? mount the posts on the outside of the wall?
byronkw is offline   Reply With Quote
Reply

Tags
exterior, flashing, post, wall cap


Thread Tools Search this Thread
Search this Thread:

Advanced Search
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
Flashing question where eavestrough meets stucco wall? chadurban Roofing/Siding 3 12-31-2010 05:42 PM
J-Weep / Flashing for exterior cultured stone veneer wall. Spud Building & Construction 18 08-31-2009 09:44 PM
Does this roof to wall flashing look right? jiminvabeach Roofing/Siding 9 01-07-2009 09:20 AM
Marrying a sloping stone wall to a cinder block wall. mrdol Landscaping & Lawn Care 1 11-09-2007 04:08 PM
Flashing for Brick Wall sandyman720 Roofing/Siding 5 08-08-2007 10:05 AM




Top of Page | View New Posts

Copyright © 2003-2014 Escalate Media. All Rights Reserved.