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Small Cabin Forum / Cabin Construction / Raising/Tearing Roof off for new Trusses
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Royalwapiti
Member
# Posted: 11 Jul 2021 11:02
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I just bought a old lake cabin 15' x15' with 2 additions. One addition is modern on a pressure treated foundation that is 16x 16'. But he tied the roof line into the hip roof of the original cabin and it is dorky looking. The other addition extended the original 15' cabin another 8 feet toward the lake with a sloped flat roof. Each has a different roof line. It needs new shingles and I guess sheathing and beside being ugly, I just want the whole roof gone.

My plan is to somehow cut the roof off in pieces and raise it off. I will likely use a crane because I have cabins 5 feet on each side of me. I figure the money spent on a small crane would be better then cutting the roof into smaller man handle sized pieces.

Two sections have a hip roof and one has a flat sloped roof.

Planning this for next Spring. Will place 16' trusses on length of roof, new sheathing and shingles. Some walls will need to be raised to get the trusses on the same level.

Any tips or pointers. Special saws or saw blades for cutting? Just cut along the top plate? Braces?

Thanks

Brettny
Member
# Posted: 11 Jul 2021 14:37
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Have you sourced and priced out a proper sized crane?

As for saws just s reciprocating saw and circular saw should work fine.

toyota_mdt_tech
Member
# Posted: 11 Jul 2021 14:50
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How about have the trusses engineered and built, then plan for a delivery date, then when its all coordinated, you pull roof off in advance and when they deliver them, have them set them all up on the top wall plate, stacked in the right order, then you slide into place. Most truss places have a crane and will do roof top delivery. The one who dropped trusses off for my attached garage at home even lifted the large header beam in place for the 16 foot garage door for me while he was there.

Steve_S
Member
# Posted: 11 Jul 2021 15:13
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Reciprocating Demolition blades or the Fireman blades (not cheap) work a treat.

I hope you get get into the roofspace and see what & how it is all put together. The trickiest spots you will have are where roof additions have been made onto the original roof structure. There is always some sort of bodgery that can come back to bite one, if not prepared for it.

The adage of First On is Last Off applies to this. The original roof segment is going to be the last to come off, because the additions build on top of it, so to speak, so you have to pull off the most recent, the next recent and so on.

I understand your desire to use a crane and that may work, depending on if these can survive being moved in sections. If you have to add bracing & blocking and it's crazy, there's no point in trying... your also wasting money then. You'd be seriously pissed if you lift a section 4' and it collapse's into pieces and falls through to the floor or worse.

The existing shingles, sheathing below does weigh a lot more than most realize (even worse if wood is puny) and that is sitting on a frame that will be extremely compromised the moment it's cut free. You'd really have to strip that off and fire it down a chute to a dumpster bin first, crane or not.

I would also suggest for the new roofing, that you might consider Corrugated Tin with a CondenStop treatment (prevents condensation under it and is a sound absorber). It is lighter than shingle and easier to install on a fresh build roof. A lighter coloured roof will also significantly reduce the amount of radiant heat it will collect during the summer which ultimately increases the heat load on the house to cool. There are different options depending on how you will insulate your roof area to cool/vent the roofspace as well, which you can leverage for energy efficiency.

A final thought as well, Solar Technologies have dropped in cost a great deal over the past few years and as we all know grid power can be peculiar and depending on where you may be, downright unreliable. When designing & building a new roof, it is the perfect opportunity to consider adding solar or at least making provisions to add it in the future. Because this is the time when considering angles & profiles for optimal solar gain.

ICC
Member
# Posted: 11 Jul 2021 16:32
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This is a big job, or rather jobs.

As Steve_S mentioned you need a "discovery" period. That has to be before trusses are ordered. Trusses are made to fit a structure. You cannot, or at least should not move the engineered support points for example.

You mentioned other cabins on each side. Is this location governed by building codes and permit needs? That may influence what and how you do this.

Are the existing roof sections built using factory made trusses or are the roof sections rafters and rafter ties, nailed to gether on site? Site assembled rafters are going to make it very difficult to remove a section of roof assembly in large pieces. My brothers firm has lifted entire truss roof assemblies using a big crane in order to make a second floor addition. Those worked well but were done to structures that had factory-made trusses.

Shadyacres
Member
# Posted: 11 Jul 2021 16:45
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I know cranes are not cheap , could probably hire a crew to do it till you pay for the crane. Unless you have access to one.

Royalwapiti
Member
# Posted: 11 Jul 2021 19:37
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Thanks for the feedback. The original 15’x15’ had a hip roof, built in 1910. The second addition is 8’x15 and looks like a enclosed screen porch with sloped flat roof. Built in 1950. Flat roof is attached to end of hip.

The third addition built in 1991 is on other end of cabin from the sloped enclosed porch. The last addition is 16’x16’ and is aligned on one side wall. Which sticks out from other side from original wall. The ridge line is the same as original cabin. To do this with the same side pitch he dropped the wall on one side of the addition. Side wall is 6’ tall along one side.

None of the roofs are engineered, built in place.

So the plan should be do it sections in order they were put on. The new addition first, which is closest to the yard and road so would be the easiest.

Peel off shingles, cut sheathing off and cut rafters off in pieces. I have circular and reciprocating saws.

I thought a crane might be best so I didn’t have to remove shingles and sheathing separately. But I can see safety being an issue with big pieces. I’m actually afraid to walk up there I have no idea the condition it’s in. No apparent leaks but still…

rpe
Member
# Posted: 12 Jul 2021 06:28
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How will you deal with potential rain damage to the finished interior while the roof is off? This doesn't sound like a one-day project.

Irrigation Guy
Member
# Posted: 12 Jul 2021 07:26
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My first thought is a Lull. You could probably rent one for a week for the price of a crane and operator for a day.

toyota_mdt_tech
Member
# Posted: 12 Jul 2021 08:13
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OK, so original is rafters, not trusses, you can make those on the fly.

Pick a long period with no rain in forecast, get lots of buddies together and bring lots of food, feed them all and feed them well at end of day.

Dont feel bad if you dont get it done this year, plywood sheeting prices are stupid and probably peaked or close to it (all lumber actually) and will probably start to come down, so this project will cost you a stupid amount of money right now.

Do you have pictures of the structure? Have a co worker who tore the entire roof off his home he lived in in a weekend and got it all done. He didnt even disturb his ceiling in his house. He had lots of friends and family helping.

gcrank1
Member
# Posted: 12 Jul 2021 10:21
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You might want to use the place as is and define what you are going to do come Next Spring

NorthRick
Member
# Posted: 12 Jul 2021 13:34
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Whatever you use to cut the old roof off, use bimetal blades or carbide tipped blades. No mater how careful you are, you will hit nails. Regular wood blades get trashed in a fraction of a second when you hit a nail.

Royalwapiti
Member
# Posted: 12 Jul 2021 16:52
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I am thinking on this more and more and it is definitely a next spring project. It has to happen in segments too. Thinking of leaving the original hip roof on it, and fixing the flat roof first. Make it the same ridgeline as existing hip roof with a gable end.

Whoever said take time to study it is correct. I need to strip the interior to what I have firstmost. We would move out during construction.

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