Addition and New Roof on Whole House


I plan to have a front portico addition to the entry of our house as shown in the linked image . The portico will be 8 ft W x 5 ft D and I have two valleys where it will tie into the existing roof. The portico general contractors says that the all the roofing for the portico and whole house should be done at the same time for the best job. I agree since one contractor is responsible for the job, but I rather have my preferred roofer do the roof.

What is the best way to spec , schedule and weather protect job if the GC did the addition w/o the roof and my preferred roofer did the whole roof ? What issues should I consider if the split the roof job between the two contractors ?


If you have a roofer lined up, ask him if he’ll dry it in for you until they can get to it. A well done dry in with synthetic underlay or ice and water can hold up for months.
Shouldn’t be too large of an expense


Why not let the GC handle it? It’s what they are paid for. If the GC is qualified to do the addition he is likely more than qualified to install a roof. Most GC’s would insist on doing the roof or would offer no warranty. The roof is only supassed by the foundation in importance. Personally, as a GC and roofing contractor I would pass on the job. With that being said.

The only simple answer is to tarp the entire roof. Unless you tarp it your self you can expect to be charged for the tarps and labor to install said tarps.


Your instincts are spot on!!
I would never let a GC do my roof.
They are shoppers of the lowest paid worker.
All they are concerned with is timelines and legal paperwork and a really low
Those ignorant of their worth are also ignorant of basic roofing techniques.
Yes, choose your preferred Roofer.
Where roofing is all they do!

Have your preferred roofer come give a proposal along with your knowledge of what the new sq footage of the porch will be.

Your roofer will need to come and put the underlayment on after the GC gets the sheeting/decking put on.
I wouldnt let the GC do that or
Choose your material.
Dont let him have control over your roof replacement.
And i dont care that he holds a roofing licence also.


This is horrible advice. GC’s are not all builders. Builders are the cheap cut all corners guys. GC’s like roofers can be both good and bad. Most general contractors are concerned about their reputation and will work to insure your satisfied. The down side is your going to pay around 10-15% more for a GC to handle the job.

Either way, it’s your house. If you want to use a specific roofer then do it. If the GC won’t agree to it just find one that will.


I stand by my statement that i would not let a general contractor do my roof.
I would want someone on my roof that roofing is All they do.
Not concrete one day, drywall the next, painting the next day, next day putting up a fence.
I want a Roofing contractor that roofing is all they do professionally
No other claims in their business name.
This assures me they are passionate about one professional trade.
That all they do is live, sleep and dream about roofing.

You can have a jackass of all trades on your roof if you want to. But i wouldn’t.


More bad advice from roof_lover. People should do their due diligence and decide for themselves. Don’t let unqualified scam artist bully you into limiting your options.


You should follow your instincts and use your preferred roofing contractor.

Dont let the GC bully you into replacing your entire roof because you are having a small entry porch built.

Dont worry about your GC denying a warranty
Your roofer will give you that warranty.


Yes, the roofer is going to warranty the facia, soffit, interior dry wall, flooring, exterior coverings, structural lumber and even the foundation. Really, they will. lol. Not going to happen.

Once anyone outside of the GC’s workforce and/or his/her hired subs do any work on that addition most warranties will be void. It’s just common sense. The roof has the ability to damage everything under it if not installed properly. The GC is not going to be liable if someone outside of his control causes damage. No court will enforce a warranty if there is potential third party liability.

Even if the GC agrees to keep the warranty in affect he/she knows it’s unenforceable one someone outside of his employ does any work to the addition.

I have no vested interest in the OP’s project. It makes no difference to me if a GC or stand alone roofer completes the job. However, there are pros and cons that must be weighed.

Here is my honest opinion.

If you are replacing just your roofing system. Find a roofing contractor (licensed and insured if applicable).

If your roof is being completed as part of a bigger project. Hire a GC and let them do their job. Or, be your own GC and manage the job your self.

The solutions above protect the property owner by keeping warranties intact , and assigning accountability to either the roofer, the GC, or individual contractors that you will manage.

Most contractors understand contracts and the laws that govern them. Some don’t.


If your General contractor wants to be an asshole
And threaten not to give you a warranty for anything
Because you didnt give him the whole roof…
Then simply have the roof installed first.
Or choose someone who isnt going to be an asshole.


Wow, I actually misread the OP on this. I apologize completely. I didn’t realize the GC was insisting on completing the entire roof. I thought we were talking about only the roof over the addition.

If the existing roof is in good shape there is no reason to replace the entire roof. If the GC is insisting on replacing the existing good roof you should find a different GC.

Again, I apologize! I


Charles_Anderson No, problem.

We are talking about both the portico addition w/roof and the roof replacement on the existing house (tear-off). The roof on the existing house does need replacement. So, the GCs want to do the roof replacement on the existing house along with the portico roof, stating this would best to do both at once.

My thought is to split the job based on some contractor input/estimates received so far, but I could be wrong. So, I am looking for input pro/cons of option each option 1) the GC does the both portico and existing roof replacement 2) splitting the job between the GC and roofer.

Part of the question is what parts of the job to split/scheduling considering in accountability, warranties, and quality. New gutters are part of the job.


If your existing roof needs replaced it would make sense to replace it at the same time as the roof is being installed on the addition. At minimum you would want to purchase all the shingles at one time ensuring they all have the same lot/batch number. This will avoid color variance caused by multiple batch numbers.

As far as warranties go. You’ll have a conflict as either contractor could try to pin roof defects or roof failure on the other. This conflict would extend to damage caused to the structure as a result of roof leaks.

If you are wanting to save 10-15% on the roof install I would suggest limiting the scope of work completed by your GC. In simple terms, have the GC do everything up to and including installing the roof deck. Then have your chosen roofing contractor complete your roof immediately following the GC.

This would allow the GC to warranty the structure and the roofing contractor to warranty the roof. Of course, any damage caused by a leaky roof would be the roofing contractors responsibility.

The problem you may run into is the GC may not be willing to limit his scope. If he isn’t willing to work with you. Look for another GC.

You will need to stay on top of scheduling as it is crucial that the roof installation happens immediately following completion of the addition. If any weather damage occurs due to lack of roof installation the GC will not be liable

I think the easy thing here is to have the GC handle it. He gets paid to ensure the project is organized, scheduled and completed on your terms. Keep in mind that most GC’s use subcontractors to complete a given project. So the people doing the work will likely be skilled professionals that the GC has worked with in the past. In many cases, the same subcontractors that would complete your roof if using a stand alone roofing contractor.


This is being over thought.

If you want your roofer to do the entire roof have the GC tear off and dry in what he does and when the GC is done the roofer can do the entire roof.

The GC is the one responsible for the water tight condition for the addition phase.

It’s not that hard to make stuff temporarily water tight, we do it all the time, daily even.


As usual, Axiom is dead on. Chances are, the roof replacement is as much or more money than the small addition. Why pay the GC’s overhead and profit if you have a preferred roofer already?

Sounds like the addition is relatively small. Why not just have the GC dry it in with ice and water shield? Then the roofer can do their part when available. Have the roofer come by promptly when it is complete to verify it is dried in to their satisfaction.

KISS. Keep it simple stupid.