Question about iframes

[Liz]

I'm in the middle of redoing my static Web site in PHP, and the siteheader (which includes all my main navigation) is a PHP document. I'm thinking of having my forums use this siteheader PHP document through an iframe. Only the forum would use the iframe, and nothing else. This would allow the entire siteheader to appear above my forums.

Currently, the siteheader does not appear on my forums at all. The only thing at the top of my forums right now is a banner with my Web site name. In this state, the forum is indexed by search engines.

My question is this: would using an iframe to get the siteheader on top of my forums somehow hurt my forums' SEO? Right now, there is no siteheader on there at all, aside from that one banner with my Web site name on it. Is this something I should be concerned about, or will it make no real difference since there's no siteheader on the forum at all right now?

Thanks!

[Chris]

I wouldn't do this for usability reasons. There will be no real SEO issue with it, but it would be better all around to just add your header directly to the forum top (like on this and almost any other site) is there a reason why you cannot do this?

[Liz]

Well, I use IPB. I want a random photo to appear in the header (so I won't have the same boring photo there all the time.) The random photo goes alongside my main navigation in the entire Web site. I have someone making a forum skin to match my Web site, with the siteheader on top, but he can't get the code for my random photo to work there. So he suggested he'd just put the siteheader PHP document in the iframe and that would take care of it.

If the iframe doesn't work in certain browsers, would that mean that my entire forum wouldn't appear at all, or would the forum simply appear without the siteheader in those cases?

Thanks for your feedback.

[Chris]

It'd mean the forum would not have the siteheader, but would otherwise work.

I don't use IBP, never have, but doing this would be very easy with vbulletin.