It's all in the design. All Grub® are 100% waterproof keeping feet warm, dry, and protected in harsh weather and messy working conditions. The secret – our exclusive self-insulating waterproof CR-foam shell construction. The CR-foam bootie material acts as a "neutral medium" between inside and outside temperatures. Naturally lightweight, buoyant, and very comfortable, the material keeps the foot and lower leg warm and protected in cold and wet conditions.
Natural rubber overlays act as a protective skin for the upper bootie. The upper has a triple reinforced toe area and a quadruple reinforced heel area. The outsole is made of high abrasion natural rubber. The rubber in the boots will stay flexible for years.
How are Grubs Boots sized?
Standard U.S. sizes for men and women (unisex sizing). Boots and shoes are available in whole sizes only, but will stretch to fit half sizes. There is a 15mm toe allowance built into the sizing. Our boots and shoes are made to standard widths, but the materials will stretch comfortably to fit widths up to a EEEE. For narrow feet, we suggest wearing a thicker sock or putting in an additional sockliner to take up room.
Are the collar and calf stiff?
No. The upper calf and topline areas are made of soft, flexible CR-foam and will "stretch-fit" to virtually any calf girth. With the flexible upper, the pant leg can be worn over or inside the boot. The collar material can be turned down to allow hands-free removal and vent humidity in warmer working conditions.
Should I wear thick socks?
It isn't necessary unless activities are planned for extreme cold conditions. The CR-foam bootie material is rated sub-zero during active use and will effectively withstand freezing temperatures for up to one hour. Medium-weight athletic socks should provide the best fit. The upper will stretch to accommodate thicker socks.
How does CR-foam compare or rate against Thinsulate® and/or Gore-Tex®?
Thinsulate®, made by 3M® Corporation, is typically used in work boots and hiking shoes to resist cold temperatures. Thinsulate® is typically laminated to the whole shoe lining or glued into the toe area of a shoe or boot. It is not a waterproof material. Gore-Tex® is a breathable, waterproof membrane but is not an insulating material. The CR-foam used in Grub's® is both waterproof and self-insulating. Our materials exceed the long-term effectiveness of waterproof membrane materials and provide greater insulating properties than all non-specialty temperature-control substrates.
Does this footwear allow your feet to breathe?
Unlike many pac boots, Grub's® do not have an inner felt liner. Felt liners are very hot and can cause skin irritation with prolonged use. One of the most important and revolutionary features of Grub's® footwear is the structured, breathable Airmesh™ lining used in all our products. Airmesh™ is made up of thousands of tiny vertical fibers that allow air to circulate throughout the interior lining surfaces. Excess humidity and perspiration that might build up in the boot are quickly wicked away. This creates a comfortable environment for your feet that lasts for extended periods of use.
How do you care for and clean these products?
The rubber shell and nylon upper are very durable and clean up easily with a spray of water or gentle scrubbing with soap and water. The rubber upper can be conditioned with wax polish or a liquid detergent. It is not recommended to use conditioners on the outsole areas. This may cause it to become slick in wet or icy conditions.
Can the rubber be repaired if punctured?
Yes. The natural rubber can be repaired with sealant found in local hardware stores. We recommend Goop® brand marine sealant. First, clean the punctured area thoroughly with mineral spirits. Then, apply the sealant over affected area and wipe to a thin film. The sealant should air dry for at least 24 hours.