Pour Foam Method - Pour/Trim/Deck?

[76SeaRay]

I am familiar with using pour foam having used it on hot tubs before and I understand the approach for drilling holes in the deck for the foam floatation then plugging them. However, it was pretty clear that the foam had swelled the floor when it was originally poured at the factory and the breakdown of the plugs on my boat was the method of water intrusion that got to the unprotected stringers. That said, I saw a Youtube video where they poured the foam without the deck installed then used a thin flat saw to trim the foam flush with the top of the stringers and ribs. After trimming they installed the decking so this way avoided holes in the deck. Is this method a valid approach that won't cause any problems?

Thanks.

 

[kcassells]

Poured foam adheres to the underside of your new deck hence creating a real nice solid deck. This really is the method of choice and compensates for all the misgivings stringers/bulkhead install have.
If foam makes your deck rise then IMHO then the underlying structure install was bad. Very typical of boat mfg. They do crappy production work to pump them out.
You can use the method you described then after you cut out the closed cells they then become OPEN cells. You need to resin the complete cut flat tops to then prevent water intrusion.

 

[76SeaRay]

I think the floor bulged up because they didn't bed the stringers and just left the foam to do the job by flowing under the stringers and ribs. I will bed the stringers and go with the plug approach. Thanks.

 

[gm280]

I agree, if they used a saw to cut off the excess closed-cell foam to level it with the stringers and bulk heads, then you basically defeated the purpose of using the pour foam in the first place. I installed my flooring and then cut about 2" holes in every section between the stringers and bulkheads. Then poured the foam, allowed it to expand, then filled in the cut out plugs and fiber-glassed over them. And if you want to know if the foam filled an area, feel the floor for heat. If the foam reached the entire section, the entire section will be fairly warm to the touch, as opposed to the rest of the floor. Easy to do and there should be zero reasons for any floor to bump up with poured foam expansion if the floor was installed correctly. JMHO!