Thru bolts or Thunder bolts

qaz123

Looking for some advice. Putting up a small roofed area 4m X 4m with 8ft high RSJ. Wondering what's thes easiest way to bolt them to concrete floor. Was thinking of using thunderbolt .

Wondering are they strong enough or would through bolts be better.

How long would I want to let concrete cure before drilling and fixing baseplates

DBK1

https://www.boards.ie/discussion/2058215172/thru-bolts-or-thunder-bolts

I definitely be using the thru bolts for something like that. They'll be about twice the price but for the size of a shed you're talking about its only going to be an extra €70 or €80. Thunder bolts are fine for hanging a small gate on a mass concrete wall but anything more than that I wouldn't trust them.

Concrete should be left 28 days to harden but you'd probably get away with it a week or 10 days sooner than that.

Cavanjack

https://www.boards.ie/discussion/2058215172/thru-bolts-or-thunder-bolts

Through bolts would be best for that job.

Id be giving the concrete a couple of weeks before drilling.

qaz123

Thanks lads for the feedback

SuperTortoise

Thru bolts or threaded bar and chemical anchor are your 2 options.

qaz123

https://www.boards.ie/discussion/comment/118091791#Comment_118091791

Haven't used chemical anchor before. What size threaded bar would you recommend. M12 would suit holes in steel baseplate but could enlarge them if I needed M16

Might work best because baseplate near concrete edge afraid thru bolts might crack concrete

SuperTortoise

Just be aware if you go for chemical anchor you'll need to drill out a 20mm hole for a 16mm threaded bar, don't know if that would suit existing baseplate holes or not, even if you go for thrubolts I would use m16 for that size shed.

patsy_mccabe

careful with threaded bar , as strength probably unknown. At least with regular bolts, you will see the strength stamped on the heads, 8.8 10.9 12.9 etc