extend deck questions

Hello,
We have an existing deck off a portion of our house that is sort of an inset so all but one side of the deck has house along it. The width of the side without a section of house is 18 feet. It sits about 3 feet off the ground. There are 2 2x10x18 foot pieces of microlamb (?? I think) sandwiched together here and there are no existing posts in the ground. We would like to extend this out about 12x18 feet.

I am wondering if i can hang my joists from this without issue to help carry the load of the addition? If not should i add a couple of posts to this to help or i am better off just building a freestanding addition that buts up against this perhaps?

Last, do you need to get a building permit to do this do you think?

Any thoughts or ideas welcome.

Thanks.

 

A little difficult to follow without pictures. Can you provide a few showing what you have and where you want to extend it? http://www.doityourself.com/forum/el...your-post.html

Is the Microlam pressure treated? Generally if you are changing the footprint of your house (which you will be doing) you will need a permit. Check with the local authorities to make sure.

 

Thanks for the response and I did try and upload a picture but for some reason it is now allowing me to do so. Keeps telling me it is invalid. It is about 2.5MB so not sure if that is to big or what.

I will keep trying here as maybe the service is down or use one of those file sharing services perhaps.

It does not look as though it is pressure treated but is suspended with an overhang off the ground if that makes much difference.

 

trying again to upload picture. You can see how the deck is sort of set in hopefully here. we want to extend this out possibly. If this works. this is the front of our house. do you think a deck coming out to where the garage ends would like bad in your opinion?

 

Try reducing the size of your picture. The site is a little finicky when it comes to picture size.

 

smaller size try. Hopefully this round works.



Hey there it is....ok size matters thanks chandler for the assistance. You on the technical assistance forms too. ha...

 

Not knowing how the Microlam is attached to the house is a questionable area. The Microlam itself will be acceptable to hang your joists from. You will need footings and posts on the outer part to hold it all up. You will be needing to use pressure treated wood as you will be venturing out to the land of rain and snow from under the protection of the porch.

 

You can hang your joist from this microlam, but microlam's are not made for exterior use. First thing make sure there is a metal C channel galvanized cap over the microlam to protect it from the elements. Next it looks like you will need to add one post in the center of the microlam. You don't want the span more than 10' on your microlam beam. Next thing is to make sure your microlam is supported at the two ends where it is attached to the house. It must be set into the framing at least three inches and or have a double hanger that supports it. At this point you can extend the deck to any distance you want. Most counties do require a permit be pulled for this type of work.
When building your new deck extension make sure to use double 2 x 10 P.T. on the perimeter of the deck and with a 12' span you could use 2 x 8 P.T. for the joists, but a double 2 x 10 for the outside band with posts spaced no more than 10' preferably 8' and since your deck is 18' that will be 9' to the center. Dig your footers and pour your concrete approx. 3" below the grade with a rebar coming out through the top center. Once the deck is built on temporary legs then make your posts with a notch so the deck will sit in the notch go ahead and put a post anchor with a J-bolt on the bottom of the post attach the post to the deck making sure the bottom of the post is approx. 3" above the ground and then slide a sauna tube up onto the post and down onto the footer and pour the sauna tube with concrete. This way you get a perfect round footer dead in the center of the post every time. Good luck with your project