Many people do fill the box beams, and I think its a good idea if you use the van in cold weather. Search the site for “thermal bridging” for more info on this. Gary Reply
Wouldn’t you want to fill the support beam holes with insulation (great stuff) ?
Many people do fill the box beams, and I think its a good idea if you use the van in cold weather. Search the site for “thermal bridging” for more info on this.
Gary