Just had new roof placed and can see daylight?

ChrisA1993

Hi all,
I recently had a new roof placed, it was completed only 2 days ago. I went up to my attic this morning and can see daylight. It seems to be present in several different areas. One was where the air vent is which I know is normal but there was some which seems to be coming through in-between the boards going up one side of roof. I am a little uneasy as I can now see more daylight than when my old roof was present. 
Is this normal? My old roof was slate and new ones are concrete so just wanted to check incase this sometimes occurs with concrete tiles.
Any help would be much appreciated.

fenwick458

without pictures, its impossible for strangers on the internet to to say. 
my first thought would be to ask the roofer to explain..?

Carrot007

Well at my old house the slate roof had a lot more light coming thugh but ther was no underlay (which was as expected for the time built). It was ok. Biggest light was indeed from a hole but it was filled with clear sealant. Never had an issue. The new owner got it changed with boring new tiles. So dull. Probably paid attention t the buyers report I never did!

ChrisA1993

I understand it must be difficult to advise when you can't see. I tried to take a picture but it doesn't show well at all. With the previous slate it was because there was no underlay so when tiles were cracking there were holes becoming present. Now I can see slits of light coming from a few different areas. I assume as newly done this could just be where tile is meeting tiles and there is a slight gap in the boards underneath, maybe at that point it is just a clear underlay present? Just looking to see if it can be normal to see daylight or if there should be total darkness.

pramsay13

You shouldn't be able to see daylight in most places, but possibly in some.
There should be boards down as well as sarking, and then the tiles, so shouldn't be daylight normally between these.
You might have a bit of daylight were the roof meets the house, or at some of the edges of the gable end etc, but they should then be covered over by roof or tiles so no water should be getting in.
Have a quick chat with your roofer about anything that worries you.

ChrisA1993

Will do, have spoken to him a bit about it and he says that as tiles are not as tight to boards as slate were there will be a few areas where little slits of light get through if it happens to be same place where roof boards are as some of them have about 1 inch gap between them.

Doozergirl

Concrete is heavier than slate.  Have you had the loading checked by a structural engineer?  It can cause the roof to bow in some circumstances.  

ChrisA1993

I have heard differing opinions on this with roofs. I was told that yes a concrete tile is heavier than a slate tile but as you need a lot more slate tiles to make a roof weather proof the weight in the end matches up. For every concrete tiles they need multiple slate tiles therefore it tends to even out. No, i was unable to get a structural engineer and had to rely on what multiple roofers told me. I have quite a few similar houses on the next street who all have concrete tiles.

tacpot12

I'm surprised the boards have an inch (25mm) between them, they should only have about 3mm.
Are you in Scotland or close to the coast? 

Have you measured the gaps yourself? Also, it is best-practice to lay tongue and groove boards and so normally no light would be visible through the boards. Also, can you tell if you are seeing the sky or are you seeing light on the outside of the breather membrane - it would give some confidence if the breather membrane was clearly present. 

Concrete tiles are never completely flat or free of twist, so you will get some spots of light when you look out of the roof horizontally. There should not be any light when you look up vertically - look up from various points on the floor (you might need to get something to span the joists to allow you to lie down on your back close to the eaves). 

TELLIT01

I've never heard of clear roof tile underlay (felt).  I wouldn't expect to be able to see any light when looking up at a new roof. 

ChrisA1993

So I can see there is definitely some kind of clear membrane down and the light is passing through this. I had interlocking concrete tiles placed so am slightly confused as I would assume as they interlock there would really be anywhere for gaps to occur? 
I am in Scotland and pretty close to sea. The house is over 100 year old so don't know if that would make a difference with spacing between boards.