Winterizing the home.

[Falstaff]

Excellent suggestion by Stew. Easy job for a small roofer, don't let them quote high, it's a half day job. Forget rotating glitter balls and the like, very expensive and tendency to jam. Since they only rotate when there is a wind then the air would be going thru the ball or roof vents anyway.
The other side of it might possibly be too much ventilation, allowing too much wet air to come in then condense inside the attic.

 

[Falstaff]

Is the pull out bed a “truckle bed”?

Nope, I think no truckles (wheels), it slides on runners on the base. However, the drawers are on narrow wheels, which will damage the carpet, so will get converted to wider slides

 

[Stew]

Excellent suggestion by Stew. Easy job for a small roofer, don't let them quote high, it's a half day job. Forget rotating glitter balls and the like, very expensive and tendency to jam. Since they only rotate when there is a wind then the air would be going thru the ball or roof vents anyway.
The other side of it might possibly be too much ventilation, allowing too much wet air to come in then condense inside the attic.

Why would you get a roofer in? If the loft is accessible, just do it yourself. Couple of quid per vent or add a few hundred quid more to pay someone else? If I’m paying someone to do the work, I check it. It would take as long to check the work as to just do it….

 

[Paul_B]

They do look easy to install. £20 for 10 vents on Amazon.

Not sure how many vents would be needed. Guess it is a case of estimating the volume of the loft and how much each vent allows through or rate of flow possible or area of the roof instead of loft volume. I reckon there is a formula for this somewhere.

Did see a photo of a row of them installed in a straigh row across the roof at half height. Not sure that is the best way to encourage through flow of air. I would have thought low to high on the other side maybe. The back of the house i to a hillside so any airflow is along the length of the ridgeline or towards the front of the roof. The back and the side adjacent to next door is low airflow directions. It is likely that the only good flow through lap vents is to the front of the house which faces the slope of the roof. Perhaps vents low at the front and higher at the back might help with an airflow through.

 

[Stew]

They do look easy to install. £20 for 10 vents on Amazon.

Not sure how many vents would be needed. Guess it is a case of estimating the volume of the loft and how much each vent allows through or rate of flow possible or area of the roof instead of loft volume. I reckon there is a formula for this somewhere.

Did see a photo of a row of them installed in a straigh row across the roof at half height. Not sure that is the best way to encourage through flow of air. I would have thought low to high on the other side maybe. The back of the house i to a hillside so any airflow is along the length of the ridgeline or towards the front of the roof. The back and the side adjacent to next door is low airflow directions. It is likely that the only good flow through lap vents is to the front of the house which faces the slope of the roof. Perhaps vents low at the front and higher at the back might help with an airflow through.

Install as low as viable to start with. The height you saw installed may have just been as low as is accessible for them.

You want low so that the wind gets in and goes up, along the inside of the roof. If you’ve started high, it’s missed a load already. If you need more later, just do it. You’ll struggle to over ventilate a cold loft.
If there are more favourable locations for your area then go for it - they’re easy to swap to a different location if you change your mind.