PILOON
Super Star Member
"I even go so far as to "flash" the top of such a beam with strips of a product such as Nervastral, so that water falling through the deck doesn't wick in to the joint.
But before a face to face sandwich, I will try to somehow leave at least a 1/2" space between faces. This usually means using full length boards between supports.
Bottom line, I have nothing against composite sandwiched beams, just not unprotected in the weather."
Every deck I have built has some sort of protection on top of the made up beams to shed water.
Either metal flashing with about 1/2" edge that is rolled over the side or that heavy black poly that is used in window openings.
On made up beams I always add a strip of 'flextra' caulk over the seams and run my finger to ensure a tight water seal and still add some sort of water shedding 'cap'.
More recently I have used the self adhesive roofing membrane that we cut in strips about 1/2" wider than the made up beam.
I really like this as also the nail holes will self seal hence providing best protection.
I once refaced a dock that had been made 50 years prior with untreated rough wood and the builder had laid strips of galvanised tin over tha top edges before adding the decking.
That old dock structure was as sound as the day it was made!
The decking? well after 40 yrs the dog could practically fall thru.
And the dock was not 'sun blessed.
'.
But before a face to face sandwich, I will try to somehow leave at least a 1/2" space between faces. This usually means using full length boards between supports.
Bottom line, I have nothing against composite sandwiched beams, just not unprotected in the weather."
Every deck I have built has some sort of protection on top of the made up beams to shed water.
Either metal flashing with about 1/2" edge that is rolled over the side or that heavy black poly that is used in window openings.
On made up beams I always add a strip of 'flextra' caulk over the seams and run my finger to ensure a tight water seal and still add some sort of water shedding 'cap'.
More recently I have used the self adhesive roofing membrane that we cut in strips about 1/2" wider than the made up beam.
I really like this as also the nail holes will self seal hence providing best protection.
I once refaced a dock that had been made 50 years prior with untreated rough wood and the builder had laid strips of galvanised tin over tha top edges before adding the decking.
That old dock structure was as sound as the day it was made!
The decking? well after 40 yrs the dog could practically fall thru.
And the dock was not 'sun blessed.
'.