Dobkins "Workspace roof" tear off
Dobkins "Workspace roof" tear off
Photos will be posted shortly documenting the replacement of a new Workspace roof. thanks to Paul R.
I must admit that the roof over the "Workspace" had not leaked in the time that we have lived in the house, but it has had problems in the past.
Ceiling plaster repairs at Dobkins were always a reminder of the trouble Dr. and Syd Dobkins experienced over the years.
Like most flat roofs of Wright's in the 50's they originally were a built up Coal Tar, felt and gravel system.
With a couple of generations of heat applied rubber on top as problems arose.
As you can see in the picture of a scupper through the parapet there is almost no room for water to drain out. The roof being dead flat with so many applied roofs that water did not pitch to the scuppers. In essence we had a pool over head.
We knew after the tear off and all the rotted decking was replaced we would need to re-pitch the roof to the scuppers.
Sleepers 16 inches on center were screwed down to existing deck. 3/4 inch plywood become our new and properly pitched roof deck.
Cant strips went in.
to be continued...
Ceiling plaster repairs at Dobkins were always a reminder of the trouble Dr. and Syd Dobkins experienced over the years.
Like most flat roofs of Wright's in the 50's they originally were a built up Coal Tar, felt and gravel system.
With a couple of generations of heat applied rubber on top as problems arose.
As you can see in the picture of a scupper through the parapet there is almost no room for water to drain out. The roof being dead flat with so many applied roofs that water did not pitch to the scuppers. In essence we had a pool over head.
We knew after the tear off and all the rotted decking was replaced we would need to re-pitch the roof to the scuppers.
Sleepers 16 inches on center were screwed down to existing deck. 3/4 inch plywood become our new and properly pitched roof deck.
Cant strips went in.
to be continued...
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Paul Ringstrom
- Posts: 4777
- Joined: Sat Sep 17, 2005 4:53 pm
- Location: Mason City, IA
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Last edited by Paul Ringstrom on Wed Aug 24, 2011 9:20 pm, edited 1 time in total.
these pics are out of order...
the first pic of this group of six, depicts sleepers and new decking pitching to 2 scuppers.
the second pic, state of the scuppers before tear off. as the roof had more roofs applied over the years the opening became small,very small. Plus the bottom of the scupper was a couple of inches higher than the deck. The result as you can imagine was a pool of water rather than a roof that drain properly.
The third pic... we were living with one rusted cook top hood vent. Painted steel has only a limited life. For years we thought it was time to replace the "Clipper" for it performed very poorly but as we discovered the insect screen and roof vent was clogged with rust and debris.
The next two pics show replacement of rotted decking and the condition of the decking after tear off.
The last pic illustrates the new, properly pitched, decking with cant strips in place.
the first pic of this group of six, depicts sleepers and new decking pitching to 2 scuppers.
the second pic, state of the scuppers before tear off. as the roof had more roofs applied over the years the opening became small,very small. Plus the bottom of the scupper was a couple of inches higher than the deck. The result as you can imagine was a pool of water rather than a roof that drain properly.
The third pic... we were living with one rusted cook top hood vent. Painted steel has only a limited life. For years we thought it was time to replace the "Clipper" for it performed very poorly but as we discovered the insect screen and roof vent was clogged with rust and debris.
The next two pics show replacement of rotted decking and the condition of the decking after tear off.
The last pic illustrates the new, properly pitched, decking with cant strips in place.
dtc:
Thanks so much for posting these pics!
We are scheduled for a tear off of the workspace roof at the Sweeton house within the next two weeks....a few questions "for the man who owns one" if you don't mind:
About what percentage of your wood decking was rotted? Though the roof at Sweeton feels good with no soft spots, I'm keeping in the back of my mind/wallet a figure of 10 to 15% for ours.
Were the rot spots nearest the scuppers and penetrations? These seem to be the areas of stain history at our house.
Did you opt to replace the skylight given the change in pitch? We are adding pitch to a dead flat too. The 2'x8' bubble skylight dates from the late '70's or early '80's and has such a low curb we need to raise the skylight up to flash properly...we're opting to replace the skylight while were at it. (The appearance in the workspace will remain original as there is a 2'x8' sheet of frosted glass at the ceiling level.)
Thanks so much for posting these pics!
We are scheduled for a tear off of the workspace roof at the Sweeton house within the next two weeks....a few questions "for the man who owns one" if you don't mind:
About what percentage of your wood decking was rotted? Though the roof at Sweeton feels good with no soft spots, I'm keeping in the back of my mind/wallet a figure of 10 to 15% for ours.
Were the rot spots nearest the scuppers and penetrations? These seem to be the areas of stain history at our house.
Did you opt to replace the skylight given the change in pitch? We are adding pitch to a dead flat too. The 2'x8' bubble skylight dates from the late '70's or early '80's and has such a low curb we need to raise the skylight up to flash properly...we're opting to replace the skylight while were at it. (The appearance in the workspace will remain original as there is a 2'x8' sheet of frosted glass at the ceiling level.)
DRN,
What material are you planning to use?
We used Sarnafil for two sections of our roof. Both sections are flat roofed and have parapet walls with scuppers. One over the utility room and the other over the workspace. Sarnafil is a Poly Vinyl Chloride (PVC). We first applied it over the utility room 6 years ago and it is performing beautifully as expected.
More pics to be posted...
What material are you planning to use?
We used Sarnafil for two sections of our roof. Both sections are flat roofed and have parapet walls with scuppers. One over the utility room and the other over the workspace. Sarnafil is a Poly Vinyl Chloride (PVC). We first applied it over the utility room 6 years ago and it is performing beautifully as expected.
More pics to be posted...
-
Paul Ringstrom
- Posts: 4777
- Joined: Sat Sep 17, 2005 4:53 pm
- Location: Mason City, IA
7. The newly decked roof with scupper ready to receive the Sarnafil.
8. A breathable deck under layment manufactured by GAF, this replaced the common 15 or 30lb, felt paper.
9. As you can see we ran it up the interior parapet walls, curbs of the skylight
and through the openings of the scuppers.
10. Grinding a horizontal bed joint (riglet) to receive the counter flashing on the wall of the utility room.
11. Laying out the Sarnafil.
Since we first applied this material over the Utility room years previous I had forgotten how many sq. feet I had on the roll.
I feared we did not have enough for this workspace project, which would have delayed the completion of this roof in a timely fashion. We were already a little tired of living with the blue tarp each evening. It gave the workspace a very cool, Blue glow.
8. A breathable deck under layment manufactured by GAF, this replaced the common 15 or 30lb, felt paper.
9. As you can see we ran it up the interior parapet walls, curbs of the skylight
and through the openings of the scuppers.
10. Grinding a horizontal bed joint (riglet) to receive the counter flashing on the wall of the utility room.
11. Laying out the Sarnafil.
Since we first applied this material over the Utility room years previous I had forgotten how many sq. feet I had on the roll.
I feared we did not have enough for this workspace project, which would have delayed the completion of this roof in a timely fashion. We were already a little tired of living with the blue tarp each evening. It gave the workspace a very cool, Blue glow.
-
Paul Ringstrom
- Posts: 4777
- Joined: Sat Sep 17, 2005 4:53 pm
- Location: Mason City, IA
12. New deck with valley pitched to the two scuppers. Ready for roofing materials.
!3. Note the 3 levels of protection...the Sarnafil, Iceguard & decking under layment. Not to mention the copper that will be installed.
14. Adjusting the Sarnafil through the parapet.
15. Heat welding the scupper.
16. Heat welding a joint with 3 inch overlaps.
17. Getting close to the finish line...the copper coping back in place.
A view of the Utility roof (foreground) and Workspace roof.
18. Finished scupper.
Note how the Sarnafil is terminated with an additional copper sleeve.
19. Detail of coping re-installed on the parapets with counter flashing.
20. So, 6 workdays later with 3 men and myself acting as a supervisor (with hands in my pocket) are glad the project has almost been resolved.
The roofers informed me they never spent so much time on such a small flat roof in their lives. Every measurement and every angle had to be checked and rechecked before they made a cut.
I believe as a group they enjoyed the challenge of working on one of Mr. Wright's usonians.
We achieved this fine work because the roofers did not skimp or cut corners. They did not have to finish in a prescribed time schedule.
They will invoice me on a time plus materials basis.
God forbid a tornado or fire, my wife Dianne and I have taken another step in assuring that the Dobkins house will eventually find itself in a position of becoming a healthy century home.
!3. Note the 3 levels of protection...the Sarnafil, Iceguard & decking under layment. Not to mention the copper that will be installed.
14. Adjusting the Sarnafil through the parapet.
15. Heat welding the scupper.
16. Heat welding a joint with 3 inch overlaps.
17. Getting close to the finish line...the copper coping back in place.
A view of the Utility roof (foreground) and Workspace roof.
18. Finished scupper.
Note how the Sarnafil is terminated with an additional copper sleeve.
19. Detail of coping re-installed on the parapets with counter flashing.
20. So, 6 workdays later with 3 men and myself acting as a supervisor (with hands in my pocket) are glad the project has almost been resolved.
The roofers informed me they never spent so much time on such a small flat roof in their lives. Every measurement and every angle had to be checked and rechecked before they made a cut.
I believe as a group they enjoyed the challenge of working on one of Mr. Wright's usonians.
We achieved this fine work because the roofers did not skimp or cut corners. They did not have to finish in a prescribed time schedule.
They will invoice me on a time plus materials basis.
God forbid a tornado or fire, my wife Dianne and I have taken another step in assuring that the Dobkins house will eventually find itself in a position of becoming a healthy century home.
dtc:
Sarnafil is a very good product. I considered it for use here, but was concerned about embers from the adjacent, very low fireplace flue making it out of a chimney cap and damaging the membrane. Instead, we are opting for the low tech, yet very durable, torch applied granular modified bitumen roll roofing (GAF Ruberoid Torch Granule). I've used it often on commercial buildings, particularly restaurants which often take foot traffic and are subject to grease or other hot stuff hitting the roof. It typically has a 20-year life when applied to a pitched substrate. In lieu of paper based felt, we are using a fiberglass underlayment sheet over 1/4" DensDeck applied to sloped insulation board. All flashings, scuppers, crickets, and flow diverters will be copper.
Sarnafil is a very good product. I considered it for use here, but was concerned about embers from the adjacent, very low fireplace flue making it out of a chimney cap and damaging the membrane. Instead, we are opting for the low tech, yet very durable, torch applied granular modified bitumen roll roofing (GAF Ruberoid Torch Granule). I've used it often on commercial buildings, particularly restaurants which often take foot traffic and are subject to grease or other hot stuff hitting the roof. It typically has a 20-year life when applied to a pitched substrate. In lieu of paper based felt, we are using a fiberglass underlayment sheet over 1/4" DensDeck applied to sloped insulation board. All flashings, scuppers, crickets, and flow diverters will be copper.
dtc, thanks for posting the detailed account of the roof replacement...I think I finally have a good grasp of how flat roofs like yours on FLW's homes work and drain.
As for the contractor, I suspect that in my area 90% of available companies would probably refuse to even bid on such a job (even in these tough economic times) simply because of the complication involved. You'd be lucky to find someome remotely local to do the work. At the same time, anyone willing to take on such work would probably be a quality craftsman by nature so you'd probably end up with solid finshed product (cost be damned I guess!).
As for the contractor, I suspect that in my area 90% of available companies would probably refuse to even bid on such a job (even in these tough economic times) simply because of the complication involved. You'd be lucky to find someome remotely local to do the work. At the same time, anyone willing to take on such work would probably be a quality craftsman by nature so you'd probably end up with solid finshed product (cost be damned I guess!).
DRN,
Our flue from our firebox and the one for our boiler are adjacent to each other and are no more than a foot higher than the sarnafil roofing membrane.
We have not experienced any problems except a coating of gray ash on the surface near the flues. I would not be afraid of fires. It takes an extreme amount of heat to weld the seam joints and ashes that float up the flue are no where near the temperature that it takes to weld two pieces together.
JPB_1971
As for the craftsmen/roofers that worked on our project, they traveled a hour and a half to get to the job site and of course as long to get home.
They only work in copper, ceramic roof tiles and slate.
Can't speak for all of Canton but roofers here are still using EPDM rubber.
Our flue from our firebox and the one for our boiler are adjacent to each other and are no more than a foot higher than the sarnafil roofing membrane.
We have not experienced any problems except a coating of gray ash on the surface near the flues. I would not be afraid of fires. It takes an extreme amount of heat to weld the seam joints and ashes that float up the flue are no where near the temperature that it takes to weld two pieces together.
JPB_1971
As for the craftsmen/roofers that worked on our project, they traveled a hour and a half to get to the job site and of course as long to get home.
They only work in copper, ceramic roof tiles and slate.
Can't speak for all of Canton but roofers here are still using EPDM rubber.