09052013 Commercial Roof RFI

This Request for information is offered to all qualified roofers, building envelope contractors, and construction management firms.

History

The client owns a commercial building in Everett WA.  Over the last 6 years they have experienced leakage in a metal roof assumed to be over 30 years in service.  Past attempts to seal the leak using general roofing contractors have minimized leaking but after a short time, the leaks return.

The general area where leaks are encountered seems to be in the vicinity of the roof mounted HVAC unit. Known/visible protrusions through the rook include the following:

  • 2 AC supply plenum and 1 AC (recirculation) return
  • 1 – 2″ electrical supply conduit
  • Electrical service line
  • 1-2 drain vents
  • AC deck mounted with 90 degree brackets to vertex of roof corrugations.
  • All grommet-sealed roof fasteners

Roof Description

Metal roof is  comprised of corrugated galvanized steel or aluminum panels overlapped and fastened to steel beam supported sub-structure.  Roof appears to have been be coated with a waterproofing sealant in the recent past.  Slope is no more than 10-15 degrees.  Rook is clear of branches and trees and otherwise appears well maintained.

The building is approximately 35 ft wide by 26 feet deep.  There are 2-3 foot eves on all four sides and approximately 4 ft X 16 ft outside foyer area.  Total roof area is therefore approximately  1250 square feet

Description of water intrusion

Water intrusion appears to be slow but generalized since at least 2-3 entry locations are suspect.  Water damage is most apparent by staining of 3 hanging acoustic ceiling panels which are easily replaced by the owner, albeit a nuisance.  Upon further inspection above the ceiling panels, insulation appears to be wet and stained, yet has not fallen.

Some water stains appear to follow the curvature of the electrical conduit but it is not known if this is the source or the resulting path of the leaking.  Minor staining of the insulation is apparent in several places, yet it is not known if these resulted from prior leaks. In addition, condensation may be the cause of some staining.  Please express your opinions in the RFI below.

Request For Information:

  • Please review the following photographs and video and provide Community Engineering Services with information that your company would provide for a long term elimination of water leakage.
  • Please describe all contributing water sources in your opinion.
  • Please describe pro’s and cons between replacing the roof and mitigating minor deficiencies.
  • Please describe replacement roof techniques and mounting strategies for overhead HVAC unit.
  • Please describe sealing devices for all protrusions through the roof.
  • Please provide an estimate of cost for your proposed solution.
  • Please provide any details about your company that would make you ideally suited for this project including, but not limited to,  proximity to the Everett Area, Recent similar work experience, reputation profiles, community service etc.

Response Process

Please provide your responses directly to _______@____ by October 1st 2013

Your response will be reviewed by the owner and Community Engineering Services. We will select the 3 respondents for a formal RFP which would include site inspection and more durable quotation of price and costs.

Thank you for responding to this RFI and please feel free to call Dan Robles with any questions that you may have.

Support Documentation:

 

Front Quarter facing North East

Front Quarter facing North East

 

 

 

Front Quarter Facing North West

Front Quarter Facing North West

Packaged AC deck mid shot

Packaged HVAC unit on wooden deck

AC unit drain and mount detail. Note rust on condensation pipe as water source.

AC unit drain and mount detail. Note rust on NG supply line / water source.

Corrugated steel edge view

Corrugated steel edge view with ‘coated’ mounting screws

Typical utility penetrations

Typical utility penetrations

Acoustic panel staining below AC unit. Note return air duct

Acoustic panel staining below AC unit. Note return air duct

Bowing and staining of acoustic panel also on proximity to AC unit

Bowing and staining of acoustic panel also on proximity to AC unit

Saturated, sagging, and mold present in insulation proximate to AC unit

Saturated, sagging, and mold present in insulation proximate to AC unit

Generalized sagging and staining in other locations

Generalized sagging and staining in other locations

Generalized sagging and staining in line with mounting screw pattern

Generalized sagging and staining in line with mounting screw pattern

Water trail below electrical conduit. Staining in-line with screw pattern

Water trail below electrical conduit. Staining in-line with screw pattern