Types of Boots
Mountaineering boots come in a few different styles. Here are the ones to know.
Single mountaineering boots have single upper with combined inner and outer layers, and they lack a removable interior liner. These boots are often lighter and more agile than hefty double mountaineering boots (see below). They generally have less insulation compared to other styles, so they aren’t the best option for particularly cold summits or trips that will last several days in cold alpine weather.
Some have no insulation at all, which makes them great for summer use, while others will have a thin layer of protection against the cold. Because they’re thinner and made of more flexible materials like synthetic fabrics and leather, single boots are often the most comfortable style of mountaineering boot.
Double or Insulated Boots
These boots often have a stiffer outer layer paired with a softer liner. The inner liner provides insulation for comfort and warmth, and it’s often removable, so you can take it out of the boot to dry should it get wet. Some companies make hybrid double boots where the liner is sewn in, and that makes them a bit lighter. The uppers on double boots are usually made of stiffer materials, and the dual layers make them clunkier and heavier than single boots. While they’re great for cold weather, they’re not ideal for summer hiking and they may be uncomfortable on long approaches.
Plastic Shell Boots
You won't often see these for sale to consumers, but they are common in mountaineering rental shops. These boots are like double boots, but rather than having a leather or synthetic exterior, the exterior will be a plastic shell similar to a ski boot. The hard shell resists abrasions and protects your feet from snow and ice. Like double boots, they have a soft, insulating interior liner that can be removed for drying out.
The plastic shell makes these boots very durable, and while they’re great for getting a taste of the sport and/or taking on single-day approaches, they will be uncomfortable on longer treks. If you plan to mountaineer regularly, you’ll want to choose a more traditional single or double boot.
Just like with normal hiking boots, your mountaineering boot fit is crucial. Make sure that your toes are not hitting the edge of the boot and that you can walk and move comfortably without any pressure points. In order to keep your feet warm while on the summit, you’ll generally wear extra-thick socks that take up additional room in your boot. You may even need to size up to accommodate your socks—so make sure you wear thick socks when you try on boots.
It’s important to keep your feet dry while mountaineering. Many double boots will include a waterproof layer to keep out moisture, and lighter single boots may opt for a durable water repellent (DWR) finish to block snow and water. Boots with a DWR finish will also dry more quickly should they get soaked.
Depending on where you’re going and how you’re getting there, the stiffness of your boot’s sole can make a real difference. Stiffer soles are great for flat trails and ice (especially if you use crampons), but if you do a lot of scrambling up steep slopes, you’ll appreciate having a more flexible boot. Fortunately, there’s a boot rating system that can help you determine the flexibility and feel of a boot.
Depending on where you shop, you may see boot ratings to give you an idea of how the boot will feel and what uses it’s designed for.
These boots are comfortable and flexible right out of the box. Their flexibility makes them a poor match for a pair of crampons.
These boots have a more flexible upper and a stiffer sole. These are great to combine with strap-on crampons.
These boots are great winter boots that are stiff with just a bit of flexibility to allow a more natural walking gait. They will work well with more robust step-in crampons.
These boots are made for hardcore mountaineering and ice climbing. These are the stiffest soles and uppers available, and they’ll provide good support and stability as you traverse and ice climb. They’ll also pair well with step-in crampons.
Many mountaineers like to use crampons when conditions get slick. Before you splurge on a pair, consider how much ice and low-traction mountaineering you plan on doing. If you’ll encounter long stretches of ice, crampons can be helpful (or even essential). Make sure to buy a mountaineering boot that’s compatible with the crampon you will be using. As outlined above, B0 boots won't work well with crampons. Boots with a B2 or B3 rating, on the other hand, may have built-in features like crampon welts to help the crampon stay in place and give you confidence on slippery surfaces.