Flat Roof - Repair or Renew?

[phykell]

The ongoing saga of my kitchen

So now my roof is leaking... I've been up to have a look and ended up using some bitumen mastic on a couple of small holes like this one:

http://www.phykell.co.uk/diy/FlatRoof1.jpg

However, I looked at the whole roof and it doesn't look good. The bitumen is cracked:

http://www.phykell.co.uk/diy/FlatRoof2.jpg

...and the felt is in poor condition:

http://www.phykell.co.uk/diy/FlatRoof3.jpg

I've started painting the whole thing with Thompsons Roof Seal which is an elastomer based paint and is supposed to last 10 years and stop all water ingress. I'm not too confident though...

Should the roof just be renewed?

Can I really repair and make good using the products I mentioned?

 

[breezer]

could you not put a "spare" bit of roofing felt over the hole then "paint it", i was just thinking it will then give the "paint" support

 

[masona]

Should the roof just be renewed?

Yes, a waste of time keep patching it up. A low pitch roof would be better if possible for trouble free maintenence.

 

[david and julie]

We changed our(attached) garage roof from flat to pitched for the same reason.

Would agree with masona it wasn't that hard. Check with your council though, ours were ok as the original footprint was unchanged. I got in writting though just in case.

 

[masona]

You can go up to 4m high for a pitch roof and 3m high for a flat roof but check with your local planning control as some area may differ.

 

[phykell]

I'd love a pitched roof but the shape and a window in the way on the main part of the house precludes this option unfortunately

 

[masona]

If you can send a picture from a distance we maybe able to help you, I haven't been beaten yet !

 

[phykell]

If you can send a picture from a distance we maybe able to help you, I haven't been beaten yet !

Thanks, I'll post some pics on Friday eveing and see if I can illustrate the problem well enough! If there is a way of havig it pitched, I'd be really interested

 

[phykell]

OK, as promised...

Here's the back of the house and you can see the kitchen extension at the RHS:

http://www.phykell.co.uk/diy/HouseBack.jpg

This is on top of the kitchen extension and you can see the garage complete with pitched roof at the side of the house. Note how close it is to the neighbour's flat-roofed garage and kitchen extension. One particular feature is that the garage intersects the kitchen extension:

http://www.phykell.co.uk/diy/FlatRoof7.jpg

You can see this also from inside the kitchen - note the door into the garage and the one into the house:

http://www.phykell.co.uk/diy/KitchenGarageIntersection.jpg

Lastly, here's a picture showing the back of the kitchen extension, the side of the garage which sticks out further to the side than the kitchen, and of course, the bathroom window which sits low and limits the pitch of the roof:

http://www.phykell.co.uk/diy/GarageKitchenBackView.jpg

Hopefully that's enough to give you an idea!

You can also see I've got my work cut out!

 

[masona]

the bathroom window which sits low and limits the pitch of the roof:

No, that's okay, it can be done !

At the moment I can think of 3 difference idea of pitch roof ! I think the best one and the cheapest would be in picture no:2 is to carry on from the pitch roof you already have and pitch the roof to the other side all the way through. You will need building permission and not planning permission for this as long the pitch roof is no higher than 4m from ground level.

 

[phykell]

OK, here's what I think it looks like:

http://www.phykell.co.uk/diy/BackView1.jpg

Are you suggesting carrying over the pitch like this:

http://www.phykell.co.uk/diy/BackView2.jpg

(bold line indicates the other side of the pitch)

So there's an apex at the top? I'd need to measure up and see if it came under the bathroom window, though thinking about it, it's not too difficult to raise the bathroom window (this is getting compex!) I guess this would require some brickwork at the front of the kitchen then or blocks perhaps? Wouldn't an apex roof and the necessary brickwork be very expensive? I wonder how expensive it would be versus renewing the flat roof? I have no idea what this figure might be but if a flat roof renewal cost (say) £1,000 and a nice pitched roof cost (say) £1,500, I'd go for the latter

 

[masona]

it's not too difficult to raise the bathroom window

I think you will get away with it.

I guess this would require some brickwork at the front of the kitchen then or blocks perhaps?

You don't have to as you can extend the roof rafter overhanging.(pitch roof all round and no gable end wall) You need to get the okay from building control which is straight forward and then take the drawing to Truss frame company who make some trussed frame which you join together, this is the cheapest route.

Wouldn't an apex roof and the necessary brickwork be very expensive? I wonder how expensive it would be versus renewing the flat roof?

At this stage, renewing the flat roof would be cheaper but depend what your long term future is. If you're planning to stay for long term then pitch roof is cheaper in the long run plus a saleable point.

My 2nd idea was to build a wall on top of your exsisting walls to approx 1m high above the flat roof all round and put in a internal roof inward which will still miss your upstairs window.

3rd idea was to build a wall all around as above and have fibreglass flat roof done by a roofing specialist which deal in balcony for walking on. The window above may need to be change to french door for stepping out onto your roof garden with some nice plants and a patio set with a glass of wine and erm, hang on I'm getting carried away here
ps: If you can't have a french door above how about a nice spiral staircase on the outside, I've done it again, more idea

 

[phykell]

You don't have to as you can extend the roof rafter overhanging.(pitch roof all round and no gable end wall) You need to get the okay from building control which is straight forward and then take the drawing to Truss frame company who make some trussed frame which you join together, this is the cheapest route.

OK, sounds great, but it also sounds a little beyond my ability so it's time to call in a professional I guess. I'll get a quote for a replacement flat roof as well just as a comparison but if it is indeed possibl to get a pitched roof, it'll be a hige improvement. Hmm, now I'm thinking about Velux windows - that'll really make the kitchen look good

As for the other ideas like a patio on the roof - nice but the weather precludes that option I reckon!

 

[masona]

I'm thinking about Velux windows - that'll really make the kitchen look good

The beauty of Velux window in the pitch roof can free up more space in your kitchen by having a smaller window or do away with it altogether if you have a back door for looking out etc....

The Velux window will give greater light area as well.

 

[trymybestbut]

If you do decide to just replace the felt there are two things to take into consideration. Firstly if it is not going to take any foot traffic then you would be far better off having a solar reflective finish, i.e. limestone chippings as they would reflect heat away from the felt causing less damage over the years. If there is a need for regular traffic in the way of cleaning windows then have this route only protected by recommended tiles to form a walkway, or if you are going to use it for social purposes tile the whole thing. Felt roofs don't like any traffic on them at all and even green mineral finish should only be used when the fall of the roof is too great to put chippings on (shed roofs for instance). [/b]