Overloaded Roof: To strengthen or replace?

[chr1s1]

Hi all,
I have a small terrace from the 1800s. At some point the slate tiles have been replaced with concrete and there is evidence of deflection of the roof (apparently the purlins and ridgeboard have been overloaded). A suggested fix is to strengthen the roof (using steel work), which comes at no small cost. I wondered if one option could be to strip the concrete tiles and to revert back to slate? It seems to be cheaper. An engineer suggested that the strengthening would not fix the problem, but stop it from getting worse. Is changing the roof covering equivalent in that way?
Thanks!

 

[freddiemercurystwin]

Why not ask you SE, seeing as you seem to have engaged with one?

 

[chr1s1]

A fair question! There were a few aspects of the service from the SE that I was not too happy with. I was looking for a space to sound out an idea before engaging a second engineer.

 

[SFK]

I am a diyer.

Perhaps you could consider future ability to sell the house.

Strengthening the roof will highlight that you have an issue to any future perspective buyers. This will decrease value.

Changing back to tiles should keep value of house as you have removed the defect, so it will not be highlighted as an issue by a future valuation engineer. Slate tiles might also improve kirb appeal.

Hence if both cost about same replacing tiles is best.

Sfk

 

[chr1s1]

Thanks, Sfk.
I had not thought of the longer term implication of how people would view the strengthening work. Slate is definitely more attractive too!
I wonder if reverting back does remove the defect? Or if there would be weakness that still needs addressing.

 

[sxturbo]

could put slate look fibre cement tiles on the roof as this is even lighter than slate

 

[chr1s1]

I've not heard of these before, I'll take a look!

 

[cdbe]

If you have a central spine wall the ridge board can easily be supported off this. The purlins can be strengthened by bolting steel (flitch) plates to them.

 

[datarebal]

could put slate look fibre cement tiles on the roof as this is even lighter than slate

Natural slate will far outlast CF slate. Also you have some sagging , to get this out 100 percent won't be easy . Any slight dip or bump will show on a CF slate.
where as , a 250 x 500 natural can be laid over most humps or dips without any cocking .

 

[chr1s1]

If you have a central spine wall the ridge board can easily be supported off this. The purlins can be strengthened by bolting steel (flitch) plates to them.

There's a bit of asymmetry to the layout, and the ridge board isn't directly over a central spine wall. Not sure that this would be an option (nice if it were though!).