Introduction : Reroofing
is categorized according to one of the following four methods;
- roof repair
- roof restoration (resaturation
- roof retrofit (recover)
- roof removal and replacement
Roof Repair is
repair work of actual leaks and obvious deteriorated areas on
an identified, localized basis. Good repair work generally requires
highly skilled roofing experience in defect identification and
proper repair procedures. Barrett materials are well suited
for roof repair work utilizing traditional repair methods.
Roof Restoration, or
resaturation, is an intermediate step between repair and retrofit,
and generally includes a repair procedure for all flashing
and a resaturant type liquid with an optional fabric or mat
over an entire roof area.
This procedure is rarely cost effective
in the long term. Barrett generally does not recommend the
use of their materials for this type of application except
as a short-term or temporary solution.
or recover, is refitting the
existing roof system with a new membrane cover and all related
flashing, over the top of the existing roof membrane. New insulation
is generally used to separate the new membrane from the existing
Reroofing directly over
an existing roof membrane is not recommended by many material
manufacturers and roofing experts since defects in the old roofing
system can be transferred to any new roof covering and there
is always a high risk of trapping moisture from the existing
roof under the new roof membrane. Complete roof removal eliminates
Barrett's policy regarding
reroofing over existing membrane is a more enlightened approach
based upon decades of experience and success in identifying
and remedying defects in an existing roof.
In general, a retrofit
roof may be successfully completed if the original roofing system
is securely attached to the deck, is not significally deteriorated,
the structural deck and insulation are in satisfactory condition
and the system does not contain excessive amounts of moisture.
Making a decision between
the options of retrofit or removal of an existing roof assembly
should be based on a complete engineering study including a
moisture survey and consideration of all extenuating circumstances
which might preclude or necessitate a complete tear-off.
If the decision is made
to roof over (retrofit) an existing membrane, the following
procedures are generally followed prior to the application of
Barrett retrofit reroof system.
- It is generally a code violation
to install more than one "retrofit roof membrane"
over an exisiting (singular) membrane.
- lf the existing roof surface
is gravel surfaced the aggregate is scraped with mechanical
equipment, powerbroomed and blown clean or vaccumed. The
surface should be relatively smooth. All surfaces must
be free of dust, dirt and debris.
- All wet or deteriorated
insulation, as determined by an approved moisture survey,
must be removed and replaced with new insulation material.
All existing insulation material should be vented with
random cuts through the existing membrane at approximately
fifteen feet centers in all directions.
- All blisters, buckles, ridges,
folds, and other deformations must be cut out and patched
to provide a smooth, even surface.
- All old flashing is cut
out and stripped from all walls, curbs and other projections,
the substrates cleaned, repaired or otherwise conditioned
to conform with the flashing requirements of the new construction.
All old edge detail work must be reviewed and a new edge
detail considered for specific job conditions.
- All roof curbs, roof drains,
edge conditions and other roof projections shall be raised
or lowered as required for new elevations, if any. All
flashings shall have a minimum height of 8 inches. Treated
wood nailers are installed as required.
- All new expansion joints,
if required by the engineering survey, and all existing
expansion joints being renewed shall have treated wood
nailer curbs installed as required
- Any drainage system changes,
including new gradient slopes, new roof drains or scuppers,
are to be designed to conform with current code requirements.
- A new membrane system, insulation
and flashing accesssories are installed in compliance
with Barrett specifications.
Roof Removal and Replacement
is the installation of a new membrane
system after complete removal of all roof components above the
structural deck. This is generally considered the safest and
surest method to guarantee long-term performance.
As with the retrofit procedure,
an engineering study should be conducted with consideration
of component expansion/contraction cycles, roof drainage, vapor
retarder requirements, temporary roofing requirements, roof
projection flashings, perimeter flashing elevations, structural
system loadings, asbestos audit and energy conservation analysis.
A roof removal plan generally
requires special provisions for keeping the building watertight
during construction as well as for dealing with potential odor,
dust and noise pollution.
Many components of an
existing built-up system can be recycled. If recycling is desired
contact Recycle Inc.
Summary : The
Barrett Company can provide a number of options and alternatives
for reroofing projects with economical, long-term proven and
guaranteed results. Each reroof is as unique as a fingerprint.
Before starting any reroof project, the owner should consult
with an RCI Registered Roof Consultant or a licensed architect
or engineer. Only approved projects are eligible for a Barrett
warranty. For more information contact Barrett Technical Services