Recovering leaking garage roof, advice please?

[jaba]

My mothers garage roof is leaking but has some sheets covering the bad bits so just about keeping the serious heavy rain out for now! Not sure how long that will last! But it needs sorting soon-ish.

I need to get detailed measurements but been told the overall size is 50m² and is a flat roof with I think roof felt of some sort. Sorry I’m not anywhere close to being an expert when it comes to roofs.

Whoever built the roof didn’t add hardly any angle to it and a good amount of water ponding is the result!

Now I’ve read in a recent post on DYINOT that a little water can add to the lifespan of a flat roof, but this roof is over 20 years old and been patched several times in the last 2 years so it might be past more patch repairs!

The main joists look in good condition and look like good quality timber. Chipboard has been used to fill the gaps between joists I assume to stop the felt from dipping and support walking on, but with a few leaks the chipboard has sunk in a couple of places and added to the ponding issue.

I would appreciate if anyone can advise best method of repair and what would be the best options on cost.

• So could a new roofing material be added on top of what’s there!

• Would all the old covering need to come off or could a new part wood frame be added to raise the angle and new covering be put on top of that!

• Or could galvanised corrugated sheeting be fixed to the current roof joists and leave the old covering in place saving time and money not removing it and also not having to raise the angle of the roof?

Not to mention keeping all the stuff inside safe and dry with all these heavy showers during new covering going on!

Money is tight so would appreciate advice to best sort things keeping that in mind as it is rather a large roof!

Advice on best sites to use for quotes would be very helpful, please PM that info if not allowed in threads!
Could really do with some idea of cost but if not allowed on the site I understand.

Thanx in advance for any info and advice.

 

[vinn]

Your roof coverings will have to come off down to bare joists.
The condition of the joists can then be seen.
All reinstatement must be to falls eg 1:40
Any fascia's or edgings and flashings must also be closely examined.

That ponding is somehow good for residential flat roofs is wrong - if it was a good idea then flat roofs would be built to pond over.
The circumstances where flat roofs are designed & built for retaining water are typically special commercial/custom circumstances.

 

[jaba]

Your roof coverings will have to come off down to bare joists.
The condition of the joists can then be seen.
All reinstatement must be to falls eg 1:40
Any fascia's or edgings and flashings must also be closely examined.

That ponding is somehow good for residential flat roofs is wrong - if it was a good idea then flat roofs would be built to pond over.
The circumstances where flat roofs are designed & built for retaining water are typically special commercial/custom circumstances.

Thanx for the reply vinn

The joists can be clearly seen from inside the garage all the way up as they're not covered in!
As far as I can see all joists are in very good shape.
The joists appear to have no bending, dipping or cracks as far as I can tell.
Roof angle is probably closer to .6":40 !! but not been able to check it yet.
The rest of the garage looks in good condition, "fascia's or edgings and flashings" etc!

Could a corrugated roof cope with a lesser angle as above? (considering the current roof hasn't leaked for 20 years)

Which would the cheaper job, felt or galvanised corrugated?
Labour time required and materials for either roof type so I can compare would be helpful?
The total area is actually a bit less than I thought at 43.5m²

I've attached a rough drawing.

 

[vinn]

Its impossible for me, at any rate, to advise you further. Without photos and the challenging information you've supplied..
You would best get a roofer out to advise on site.