Water coming in to upstairs bedroom after heavy rain.

I would check for blocked gutters, also maybe the felt has now perished, we have come across this problem many times. We strip of bottom couple of rows of tiles, which you will need to do any way to inspect where water is coming in, we then fit felt refurbishment, support trays. During this bad winter, when all the gutters filled with snow and iced up,we were called out to several roofs with this problem, ie water running down the bedroom walls Simple job for a roofer

I agree with the above, buy UPVC eave protectors and breathable felt. Strip at least 1 meter up the roof. Keep the tile/slate for reuse later. Fit the eave protectors at the eave, tack nail into top of fascia, replace with a new layer of felt, tuck under the old felt above. Re-batten with treated battens, and re-tile - a pretty simple job really. If you haven't done it before ensure to measure the batten spacing from the top of the fascia to the bottom of the first batten, and then the space between each batten, so you can lay the battens out the same as before. 'Edit by myself' Just reading back on this, you should measure from the top of the fascia to the top of the batten. Its always top to top. Oops.

If you have ladders get a friend to help and pop up the ladder and look, if gutter is full of muck , take bucket up and clear out . If it happens again call out a roofer to strip a metre of the slate / tiles back and fit eaves protector boards and breathable membrane , batten and refit tiles/ slates job done

i would certainly get a respectable roofer around and check your roof where the rain could be coming in.there could be a number of reasons for this,so get it checked befor it causes more internal damage many thanks nick