Making floor flat for Garage door

[rvgledhill]

Hi,
I am having a new roller garage door fitted soon but the garage floor to which the door will come down to is not so flat tarmac.
In order to get the best seal for the door the floor at this point will need to be flat and straight.
I am guessing I can apply a layer of concrete straight onto the tarmac and work it so it is straight and flat but have never done anything like this before ??
Usually things like this are not as straightforward as they seem. Any tips/advice will be very much appreciated.

Rob

 

[JerryM]

i've not done this exact job so no expert. i have block paved upto tarmac though.

tarmac is very soft (relatively) and i feel it would be best to take it up and pour the concrete onto hardcore. u might need some turned on edge flags or edging bricks to sit between the concrete and tarmac (only for aesthetics). u will also need some patching tarmac to make good the cut edge.

 

[JohnD]

and I would do it after you've fitted the door, then you can make it a good fit and have a slight hump to make rain water run outwards and reduce draughts and dirt getting in..

It needs to be strong enough to prevent people putting a lever into the gap to get the door open

 

[breezer]

how big is the gap?

i have seen what looks like (but it isnt) pipe insulators fixed to the bottom flat edge of the door.

by pipe insularors i mean the round long stuff that you put on central heating pipes to keep them..........insulated

 

[noseall]

john and jerry have just about covered it.

you will be best off cutting a strip of tarmac out, say600mm and laying a decent mix of concrete down creating a threshold.

doing this after the door has been fitted makes a lot of sense.