Synthetic insulated belay jacket vs thicker mid layers or down

Question

When it gets colder while walking, I'd add an extra fleece as a mid layer and when we stop to eat, I would put it on too, or I'd wear a down jacket if it's dry.

However when it's wet, it seems like taking off outer shell to add mid layer is troublesome. Isn't it better to get a synthetic down jacket that can be worn on top of my shell, even if it's a bit wet? This way I can just throw it on top. I've heard this can be referred to as belay jacket.

What are the pros and cons? What have been your experiences in, e.g. Scottish weather?

PS. My shell is actually Paramo, which in my experience will be more breathable than a membrane, so I don't believe I'd be getting wet from the inside.

Answer 1

If I stop to take a break in cold dry windy weather, I am perfectly happy tossing a big puffy belay jacket on top of my shell if I can get out of the wind. If I cannot get out of the wind, I will usually take the shell off and put it on top of the puffy. Often the puffy is warm enough that it doesn't really matter.

If it is wet out, my puffy is probably not coming out of my bag. My puffy, even my synthetic puffy, does not get wet. It doesn't go on top of sweat or rain soaked mid layers and I don't exert myself in it. I tend to not take breaks in cold wet weather. Under no circumstances would I wear my puffy on top of my shell in wet weather.

If it is raining so hard and you cannot find shelter that will allow you to quickly remove your shell, add a layer, and get your shell back on, just grab some snacks and keep going.

Answer 2

In winter I will often wear a Paramo waterproof jacket (I live in the UK). If it is near to freezing or colder, then I also wear a light fleece top or jacket underneath. When stopped for any reason, I put on a Paramo Torres jacket over the top of the waterproof jacket. The Torres is a warm jacket marketed by Paramo just for this purpose (i.e. putting on straight on top of your waterproof jacket without having to remove it and lose any heat or get the clothing underneath wet).

The Torres is a synthetic-filled warm jacket treated with NikWax (like the waterproof jackets, etc.) and seems to work very well, even when it is raining . It is cut a bit bigger to allow for wearing a bit more clothing underneath.

You could probably use any synthetic-filled jacket for this purpose as the synthetic insulation still maintains some insulating properties when wet unlike down (even hydrophobic-treated down). The Paramo Torres has been designed for this function and seems to work well.