Weight of MDF bookcases on Victorian floor joists

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liambm

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Hi,

New member here, but have been lurking around for a while -- pleased to meet you all. Not entirely sure if this is the correct forum for this post, but wasn't sure where else to put it.

I'm currently building some library style bookcases with cabinets at the bottom. They'll measure 1.7m wide by 2.2m tall, and made mostly from MDF (Hydrofugo). I've calculated the total weight of the materials to be approx 220kg. Books and other items will obviously add a fair bit of extra weight.

I live in a Victorian (~1900) mid-terrace. The bookcases will be located on the first floor landing, where an old hot water cylinder used to be. They'll be positioned up against, and parallel to, the party wall. The 5 floor joists here run perpendicular to the party wall. Upon inspecting the joists I've discovered that instead of being pocketed into the wall (as they are elsewhere in the house), they sit on top of a timber wall plate, which itself sits on top of what I believe are three wrought iron corbels / bars (end of corbel circled in red):

img.jpg


The timbers appear to be fine -- a few water stains from a previous leak but no rot or woodworm (although I've treated all the timber as a precaution). It's difficult to tell the condition of the corbels, or how far they run into the wall.

My question is this: should I be at all concerned about the weight of the bookcases bearing on these three corbels? I presume they're original and so have stood the test of time, but I know wrought iron can eventually fail. The one thing that does reassure me is the fact that there was an old water cylinder here located over just one of the corbels, which probably weighed in at around 170kg, and that doesn't appear to have caused any issues.

I have thought about trying to strengthen / reinforce the wall plate e.g. by inserting threaded studs into the wall, but I fear that could be opening a can of worms and it's probably best leaving it well alone.

Am I overthinking this?
 
Personally I think you should be fine if there was no movement with the water tank, I remember removing 3 brick filled storage heaters from a 1900s mid terraced house each rested on two metal legs about 2 inches by a foot if memory serves so not much in the way of load spreading, the floor didn't look as solid as yours but held up fine.

The Wago box on the other hand only complies if you close it with a tie rap - having just prized one open I can only assume this is to make it proof against navel gun fire
 
Think of it this way.
Put as sofa against that wall with yourself and 2 friends.
Whats the combined weight on the floor ? at least 30 stone ? 30 stone being about 200kg(190)
Oh, plus the weight of the sofa so add 50kg to that

You wouldnt think twice about having a sofa there
 
Last edited:
Hi liambm. In the period your property was constructed the general concept for additional floor loading in residential domestic buildings was 40 lb./sq. ft. The level of loading was intended to include the total surface area of the floor on which domestic furniture could be placed. For general workplace loading this was increased to 70 lb./sq. ft. Hope this helps.
 
That cylinder would have weighed around 130 kg + similar weight of the feed and expansion tank usually fitted above it , the strongest point of the joists is at the point they are supported. Can’t see the support points that well you have circled in red very well but in the old days they usually went overboard. If it’s a party wall you may not be able to drill into it without the other party’s agreement. Can you spread the shelves out so they are not side by side or is this not an option ..
 
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