How much weight can a hard top hold

Being a 27 year old boat, I wouldn't put any significant live load on the hard top. You might have to comb thru some older literature to find out what it was rated for from the factory, but i can almost guarantee they said "Do not place any objects on this top". Most have that for a simple CYA.

That being said, I would argue that it would be more than strong enough to support a dinghy or stowage bags, but I wouldn't put a live, moving load (such as people) on it. But, it's your boat. Step up on it and see if it feels solid, if it cracks or pops, and go from there. But it is a heck of a tumble to the deck if it fails....juss' sayin'....

My wife was on both our hard tops waxing them. They feel fine for her, but she weights about 110. I don't feel so confident, but I weight 220.

Method 1 is to have her jump up and down and see what happens, or
Method 2: Analyse and Reinforce: What are the dimensions of the span, profile, material used and thickness, laminates, beams, columns sizes, etc. Then one can estimate the load limit...but what saftey factor? Next, what do you want to store there? Is a hoist planned? Finally, modify/reinforce as necessary. For light weight roof spans, I like curved fiberglass/foam sandwich with glassed-in I beams.

Have you tried calling Carver and asking them what the weight capacity is?

I have the install paper work for my hard top and it said NOT USE FOR STORAGE ....but as we all know folks have, I've seen a few 3607's with dinks on top, my self being on the Ches. Bay I wouldn't want it up there raising my C/L of roll higher, load knows following seas suck enough already....

I have a 1990 3607 with aft hardtop. The tag on it says no load but I have sat on it many times when working on stuff on my radar arch, Iwould not have any problem putting a dingy on it.

I too get up on mt hard top to work on radar, change lights and clean it , but if the top says no load on it why would you store something on that the makers of it said it shouldn't be there ? While I guess a higher C/L may not be a big deal on a inland lake or river (excluding the Great lakes) it sure is on water that can see 3' foot or better waves and our 3607's really suck as it is with following sea's off their quarters and a higher C/L would make them even worse .

The 3607 weighs about 19,000 lbs, the center of gravity is about 30" above waterline, adding 300 lbs to the hardtop, (about 13 ft above waterline) will move the center of gravity up less than 6". This will have little effect on stability. The 3607's handling in a following sea is not an issue of safety or stability but an issue of a large, nearly flat bottom for the aft half of the hull. Don't worry, your not going to turn this boat over unless your in sea conditions that a 40' boat should not be out in.

still why would you go against a known misuse of the hard top, C/L raise 6", weight on top and sight aft blocked. I wouldn't recommend it, IMO but to each his own

It should support several hundred lbs of one or two people laying up there in a calm harbor......I wouldn't try to make it support a dinghy and davit........

The issue is one of structural support. This hardtop is simply two fiberglass surfaces separated by a small quantity of closed cell foam with no lateral or transverse frames. Not designed to support weight in middle, if it bows down in the middle it will collapse, this being said, the flex modulus of the material indicates it will hold a couple hundred lbs of dead weight without failure.

now lets put 20 some years of age on it...I wouldn't store anything on it....

What's the logic in this?

The entire boat is 20 years old, would you not go out to sea on it? I've taken yachts 200 miles offshore that were over 20 years old, and never thought twice about the structural integrity of the fiberglass.

I think a 20 year old boat is built better than today if maintain well.

Fiberglass is like concrete, it only gets better with time, it reaches 70% cure in a few days but the remaining 30% of it's development continues over a lifetime.

I agree in many builders.