Imperfect tense and the use of "tiges"

Didot 

“ If the problem turned out to be more serious, what kind of repairs would be necessary? “

the sentence is being posed as a hypothetitical conditional phrase, so the ‘ si ‘ clause needs to be in the imparfait

Using "si" + L'Imparfait in hypothetical sentences with Le Conditionnel Présent 

https://www.lawlessfrench.com/grammar/si-clauses-second-conditional/ 

I think ‘ tiges métalliques ‘ should be accepted for ‘ metallic rods ‘, unless there is some very specific technical reason otherwise for using ‘ barres ‘ ( my wife translated this as ‘ tiges ‘ when asked ). 

( not sure the link will work unless you are in, or ‘VPN’ to France as I did )

 https://www.leroymerlin.fr/search?q=Tige 

Finally, unrelated to your question, the last sentence of the English script as written sounds clunky to me :

 “ I will prepare a detailed quote as soon as I'll have checked everything on the roof and the external walls. “ 

 In English I would definitely never say or write ‘ .. as soon as I will (I’ll ) have checked “ 

Using the same basic phrasing,  it would simply be “ … as soon as I have checked “ 

Unless there are regional differences in English that I am unaware of, this sentence should be changed, notwithstanding that the French translation will still require the 2 verbs to be in future tense.