A.
EXISTING SASH Using existing wood sash that meet the agreed
upon standard set with sample window, joints strong and
complete, surface repairable and can be billed with exterior
filler and sized for conversion methods to be used. Sash
determined unusable at time of initial inspection will
be replaced by approved new milled sash at a predetermined
price.
B.
GLASS
1.
Insulated units factory fabricated of double-strength
glass. Overall thickness determined at time of sample.
2.
Dual sealed edges using aluminum, Swiggle (manufactured
by Tremco), or Warm Edge Technology (manufactured by
Edge Tech) spacer predetermined at time of sample. Dual
seal to use butyl and Polysulfide sealant.
3.
Glass units to have factory replacement warranty covering
unit "free from moisture between the two glass surfaces
for a period of ten (10) years.
4.
Glass type, (clear, Low E, tinted, gas filled, tempered)
to be determined at time of sample.
C.
GLAZING
1.
Existing sash to be modified by cutting away existing
putty or equivalent increasing the width and depth of
the rabbit joint, and cleaning surface back to raw wood
in strict accordance with Bi-Glass specifications.
2.
Norseal (manufactured by Norton) PVC Foam gasket to
be used to back. bed glass to sash.
3.
Air space of 1/8" + or - 1/16" maintained around glass
in strict accordance with Bi-Glass specifications.
4.
Exterior glazing stop to be of milled wood or equivalent,
sealed and mechanically fastened to the existing sash.
Wood to be primed white ready to paint.
5.
Compatible glazing sealant to be used to seal exterior
stop against moisture infiltration. Sealant to meet
ANSI/ASTM C-834-76
D.
WINDOW BALANCES
1.
Type of balance system to be one of the following:
a.
existing weights and cords
b.
tilt track with one mechanical spring 700 Series (1
3/8" or 1 ¾")
c.
tilt tracks with two mechanical springs
d.
hidden balances
e.
Tape balances
f.
Type determined before sample installed. Bi-Glass
to determine best option to use considering weight,
use, and requirements of end user.
2.
Existing weights to be balanced to new heavier glass.
Weight pockets sealed to control air infiltration. Replace
cords (chains) as required. Install weather-stripping
on sides of sash in strict accordance to Bi-Glass specifications
using either or both vinyl corner seal and ribbed felt
spline.
3.
Single balance tilt track to be used when tilt in feature
is required and sash weight can be balanced by a single
spring.
4.
Double balance tilt track to be used when tilt in feature
is required and sash weight can not be balanced by a
single spring. Track size and balance spring size to
be in strict accordance with Bi-Glass specifications.
E.
Balance Component Specifications
1.
Existing weights Ropes are replaced with nylon, 3/8"
1500 lb. test cord. Sash chain replaced with plated
steel, 250 lb. test. Weights are added with 2 lb. stackable
cast iron 4" sections or pre-sized lead weights. Sash
pulleys are replaced where needed with red bronze housing
and wheel, with a steel axle, and matched to size and
weight used.
2.
Single balance tilt track: (7000 Series) Full-tilt rigid
vinyl jambliners with cellular foam backing. PVC material
is extruded .050 thickness. Block and tackle balances
are made with lubricated high initial-tensions springs,
zinc die cast pulleys, pre-stitched Dacron cord and
"knife lock" locking terminal. Cam pivot attached to
"V" profiled sash is cast zinc. Installed onto jamb
board with center, coarse-threaded, galvanized, ‘2"
screws.
3.
Double balance tilt track: (Magnum Series) Full-tilt
rigid vinyl jambliners with cellular foam backing. PVC
material is extruded .065 thickness. Block and tackle
balances are made with lubricated high initial-tension
springs, zinc die cast pulleys, pre-stitched Dacron
cord and "knife lock" locking terminal. Two balance
are used per side of sash engineered to match sash weight.
Cam pivot attached to "V" profiled sash is cast zinc.
Installed onto jamb board with galvanized steel brackets.
4.
Hidden balances: Non-tilt balances fit into a ploughed
stile of sash and screwed with top and bottom coarse-threaded
hardened screw. Block and tackle balances are made with
galvanized casing, one or two high initial tension springs,
zinc die cast pulleys, and stainless steel end mounting
clip is screwed to jamb board with hardened, coarse
threaded screw. Balance spring engineered to weight
of the sash.
5.
Tape Balances: Pullman tape balances with spring steel
tape are used in place of rope and pulley to enable
weight pockets to be filled with insulation. Balance
spring is engineered to the weight of sash. Tape is
attached to stile similar to the old rope.
F.
WEATHER-STRIPPING
1.
All weather-stripping to be installed into a saw kerf.
2.
Horizontal weather-stripping shall be ¼" tubular silicone
rubber with a saw kerf bar.
3.
Vertical weather-stripping shall be a brush with vinyl
center fin, ¼" pile, held in a polypropylene saw kerf
bard.
4.
Check rail shall be bulb covered with low friction plastic
coating.
5.
End of check rail shall come in contact with brush plug
in jambliner or parting stop.
6.
All weather-stripping shall be applied in accordance
with Bi-Glass specifications.
G.
EXTERIOR MATCHING HISTORIC GRILLS
Grills
applied to the glass when a full sheet of insulated
glass can be used. The grill is made from wood protected
with a water repellent, and primed painted. The grill
is cut and fitted to match inside muntin configurations,
and permanently attached to the glass using Norseal
exterior glazing tape according to the Bi-Glass specifications.
H.
HARDWARE
One
zinc die cast cam lock colored white or brown shall
be installed.
I.
WOOD REPAIR
1.
All filler shall be exterior rated. Latex flexible (can
be painted) filler Shall be used. Filler will be used
on surface not structural parts of window.
2.
Structural repairs will be with new component parts,
with prior approval.
