Window & Door Sealant for Professional Results
Premium hybrid sealant, ASTM C920 Class 50
Window and door frames move constantly, with temperature changes, humidity cycling, and building settling. Most caulks crack under this movement. Ours is engineered for it. High-movement, paintable sealant that grabs, stretches, and holds for the life of the joint.
10 fl oz / 300 mL · Hyper Stretch™
- 100
- 200
- 300
- 400
- 500
- 600
- 700
- 800
- 900
- 1000
The most elastic formula in the line. Ten times its own length before it breaks. This is the product the Hyper Stretch platform is named for.
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Benefits
- ±50% movement capacity, built for real building movement
- Skin formation in 9 minutes
- Solvent-free, UV stable
- Professional adhesion on wood, composite, metal
- Low odor, solvent-free formula
Product details
High-movement joint sealant, ASTM C920 Class 50.
How to use
- Treated lumber must have weathered at least six months before you seal to it.
- Prime porous surfaces in water-loaded applications.
- Skin forms in 9 minutes. Tool the bead inside that.
- Tack-free is 350 minutes, so do not paint it the same hour. Test compatibility first.
Where not to use it
From the manufacturer's datasheet.
- Not on freshly treated wood. Treated lumber must have weathered at least six months, and on a siding product that is exactly what it will meet
- Not a structural sealant. Not a glazing sealant
- Not for continuous immersion in water
- Plasticizer-containing plastics, flexible PVC, butyl rubber and EPDM, can discolour or lose adhesion
- Prime porous surfaces in water-loaded applications
- Test paint compatibility first, and note tack-free is 350 minutes, so do not paint it the same hour
Approved to AAMA 802.3-10 Type II, 803.3-10 Type I, 805.2-10 Group C and 808.3-10, and Federal Specification TT-S-00230C Type II Class A.
Documents & guarantee
Everything a spec buyer asks for before an order, in one place.
- Safety Data Sheet, Window & Door. Request a copy
- Technical Data Sheet, Window & Door. Request a copy
- Every figure on this page comes off these two documents
- Covered for as long as you own your home
- Printed on the tube, not a supplier's policy borrowed into our copy
- Family-owned and building sealant tools since 1974
- Ask us where to buy near you
- Same cartridge, same guarantee, off your usual counter
- Not stocked yet? Ask for it and tell us where
Elongation: 1,000%+ · The most elastic formula in the line
Pack Pricing
One ladder, per-tube price on every row. The ten-case tier is the floor: a quarter off, and no further.
| Pack | Order | Contains | Price | Per cartridge | Saving | |
|---|---|---|---|---|---|---|
| Single | M-WNDRSD-WHITE | 1 cartridge | $15.99 | $15.99 | – | |
| 6-pack | M-WNDRSD-WHITE-6PK | 6 cartridges | $89.99 | $14.99 | 6% off | |
| Case of 12 | M-WNDRSD-WHITE-12PK | 12 cartridges | $159.99 | $13.33 | 17% off | |
| 5 cases | M-WNDRSD-WHITE-60PK | 60 cartridges | $757.99 | $12.63 | 21% off | |
| 10 cases | M-WNDRSD-WHITE-120PK | 120 cartridges | $1,439.99 | $11.99 | 25% off |
- 1x
- 3x
- 5x
- 7x
- 9x
- 1,000%+
Diagram, drawn to scale off the datasheet figure: the bead reaches ten times its rest length before it breaks. Not a photograph.
Compare It With The Others
Elongation at break on one scale. Pick any other formula in the line and the bars show how far each stretches from the same rest length, so a 350% bead and a 700% bead read as different here as they are in the joint. More stretch is not always the answer, which is why the facts underneath say what each one is for.
The Jobs It’s For
One high-movement hybrid, and the three jobs it is for. Every one of them an opening that never stops moving.
Window perimeter
Frame to wallThe frame expands and contracts with every temperature swing, the wood moves with the humidity, and the building settles around both. Class 50 is the rating that opening asks for.
Door frame and jamb
Interior and exteriorA door frame takes the swing stress of every use on top of the building's own movement. It stays flexible under it rather than cracking along the jamb.
Siding and facade
Long exterior runsLap joints, panel transitions and facade details, paintable with house paint once tack-free, and UV stable through freeze-thaw cycles.
Sealant for Every Window & Door Application
Window frames, door frames, exterior trim, and every joint where movement is the thing that breaks the seal. One high-movement formula handles all of it.
New Construction Windows
- Frame-to-wall transitions
- Handles seasonal movement
- Paintable with house paint
- Professional appearance
Door Frames & Jambs
- Interior and exterior doors
- Flexible under door swing stress
- No cracking under repeated movement
- Professional-grade finish
Exterior Trim & Siding
- Caulking around fascia
- Trim-to-siding gaps
- UV stable and weatherproof
- Weatherproof joint sealing
Skylight & Glass Installation
- High-movement glass-to-frame
- Handles thermal expansion
- Paintable for a seamless look
- Handles ±50% movement
Why We Engineer for ±50% Movement
Windows and doors move more than most people realize. Temperature swings expand and contract the frame, humidity moves the wood, and the building settles around both. A Class 25 joint sealant is the right tool for most joints in a house. A window opening is not most joints, and this is the one rated for it. Professional window sealants are engineered for ±50%.
One formula. One movement rating. Professional durability without compromise.
Why Professional Window Sealant Matters
Class 25 covers the great majority of joints in a building. A window opening moves further than that, through every season, which is why this one is certified to the class above it.
Grabs
Professional adhesion on wood, composite, metal, and painted surfaces. Sticks through paint, doesn't peel or separate.
Stretches
±50% movement capacity. Windows expand and contract with temperature. The sealant flexes without cracking or failing. That's engineering.
Holds
UV stable and weatherproof through freeze-thaw cycles and moisture. Approved to the AAMA window standards, and covered by the Newborn guarantee for as long as you own your home.
Newborn blue, high thrust
Use the 250 or 360-DT with this one, because this one barely moves without sustained force, so the pressure stays on and the cut-off is under your thumb.
How to choose a gun →
Try it on a real joint first
If you caulk for a living we will send a cartridge of Window & Door at no charge, freight included, so you can put it in the job you would have used your usual caulk on. One request per company, and there is nothing to buy.
Professional Window & Door Sealant. Built for Real Movement.
±50% movement, over 1,000% elongation, and the AAMA window approvals to back both. Covered by the Newborn guarantee for as long as you own your home.
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