I have a wealth of experience within the painting and decorating trade in both areas of domestic and the commercial side. Ranging from interior and exterior refurbishment on newly constructed Wimpey homes and also full school refurbishments during term times. The above work was undertaken whilst living in London. I brought my business back up to Yorkshire some 5 years ago and continue in the success of offering a range of services ranging from painting and decorating/wallpapering to general house maintenance and fencing.
Yes you can wallpaper over existing wallpaper providing the old wallpaper is completely adhered to the wall.
personally i would not paper over existing wallpaper for many reasons, a few of which are-:
the joints between each piece will be visible.
depending on where the wallpapering is being done i.e living room, then it'll have to be dirt/dust/nicotine free, that kind of thing.
in a nutshell and to achieve pleasing job, i'd strip the walls and then hang lining paper horizontally prior to hanging the wallpaper vertically.
that is the correct way. however i have known people to bypass the lining paper and just hang the wallpaper.
It's difficult to comment on.
i'm assuming it's a standard hall stairs landing?
how many doors and is it both sides?
do you have a banister with spindles?
My theory is that there's a possibility the walls hadn't been mist coated/white washed. so if that is the case, then paint will not adhere hence the wallpaper paste not adhering fully.
Anybody can paint fence panels.
i creocoted 300 feather edge boards 3 weeks ago and i regard and pride myself in the quality of my day to day painting and decorating.
so in answer to your question, absolutely, fence painting is open to all 👍
If the yellow marks cannot be removed by the use of cleaning products then an application of stain block needs to be applied before applying a coat of gloss.
in regards to touching up gloss... depending on how long the initial gloss has been on the windowsill/shelf.
personally i would prep the whole area to be glossed by using sandpaper with the relevant grit/sandpaper grade. then stain block the yellow marks before applying a nice coat of gloss for an overall and even finish.