Welding Near Existing Wood - Possible?

[sticksandtriangles]

I have a retrofit project where I want to weld near some existing wood (existing tongue and groove deck and wood beams).

Sample detail:

Is this possible without starting a big fire? Will my contractor laugh at me?






S&T -

http://www.re-tug.com

 

[phamENG]

Yes, it can be done. There are weld blankets that can be hung and other protective measures. They'll need a fire watch on the roof and in the space where the welding is occurring. Not all contractors like it, and they may still laugh at you...but it can be done.

 

[dik]

It's tricky and dangerous... I've cut out 3" and 4" pipes from between wood floor joists with a torch... just have to be careful.

Rather than think climate change and the corona virus as science, think of it as the wrath of God. Feel any better?

-Dik

 

[sticksandtriangles]

Thanks for replies, fingers crossed the welding goes smoothly!

S&T -

http://www.re-tug.com

 

[dik]

Have water on hand and a second set of eyes...

Rather than think climate change and the corona virus as science, think of it as the wrath of God. Feel any better?

-Dik

 

[LittleInch]

What are you welding to what? - the angle bracket to ?? How close to the beam? Is there a view on this from the right hand side?

Try wetting the wood prior to welding and make sure they go back and look 15, 30 and 60 minutes later. Wood does some strange things when exposed to welding temperatures.

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.

 

[dik]

Thanks LI... forgot to note that I wetted the area down first.

Rather than think climate change and the corona virus as science, think of it as the wrath of God. Feel any better?

-Dik

 

[Demented]

https://www.kimballmidwest.com/801159

I've used this stuff with great success in protection of wood and glass that was near or directly in contact with welding heat. Works better than water, Fire watch is still a must though.

Precision guess work based on information provided by those of questionable knowledge

 

[dik]

thanks... on the shelf for future reference... appears to be good.

Rather than think climate change and the corona virus as science, think of it as the wrath of God. Feel any better?

-Dik

 

[Enable]

Definitely can be done. I've done it a handful and times and I cant say I've ever enjoyed it.

The contractor also has to be mindful of fires occurring well after the work has stopped. It doesn't take much for some wood fragment to get red hot and smolder in a corner where it stays undetected until a fire starts late night. I've always put smoke detectors at first night in the area for this reason. Doesn't do you much good if no one is around though (first night fire watch may be prudent).

The product Demented linked to looks very cool. I would definitely check that out.


CWB (W47.1) Div 1 Fabricator
Temporary Works Design

https://www.enable-inc.com/

 

[phamENG]

Just as a cautionary tale - I got the privilege designing the replacement for a massive church steeple and roof truss repairs on a 150 year old church because the roofer did some hot work and went to lunch without a fire watch. So it can be done successfully, but it can also be f*&^ed up pretty bad.

 

[WARose]

It can be done.....but I'd shield the wood. And (like someone else said) I'd monitor it for a while.

The wood to watch out for is any kind of evergreen (like pine). That rosin it puts out loves to burn.

 

[bridgebuster]

pham - was the entire church lost? Sorry, I misread, you came in after the fire.

 

[Enable]

phamENG assuming you reused some of the existing members where the fire didn't do as much damage, how did you assess the integrity of the existing members you wanted to reuse? Did you bring in a wood specialist or anything?


CWB (W47.1) Div 1 Fabricator
Temporary Works Design

https://www.enable-inc.com/

 

[phamENG]

bridgebuster - no, the bulk of the structure survived. The steeple was a complete loss, of course, but the main sanctuary roof was largely salvageable. The bay immediately adjacent to the steeple was badly damaged, and a few of the timbers from the chimney speared the roof and ignited part of the attic. Most of the damage to the sanctuary came from the firefighters' hoses. We have a really fantastic historic preservation architect here who spearheaded that. They did detail moisture evaluations to determine how much of the historic fabric could be maintained. He also did an amazing job pouring over historic photographs and documents to match all of the detailing both inside and out.

Enable - the reuse was only in the roof trusses. It was a small enough area that my bosses at the time felt a wood specialist would be an excessive expense. I strapped myself to the trusses in the attic and worked a scraper over the char to establish dimensions. Knocked an allowance off to account for non-char thermal degradation (1/2"? That sounds right. I'd have to pull my references to double check) and failed conservative in analysis assumptions. Now that I'm on my own, I'm seriously considering the purchase of a Resistograph and taking some courses in wood grading. As many historic buildings as I work on, I'd really like to have a more concrete educational background in some of it than is the norm around here.

The demo to remove the burnt out steeple was really something as it exposed the original construction. You can't see it well in that picture, but it's a Victorian Gothic style church with the Narthex in a square brick tower below the steeple. The brick tower was about 60feet tall with the timber portion another 100+ feet on top of it, and those timbers started 30 feet off the ground. They built the brick halfway up, started the timber tower as it sloped, and then kept the brick going. It was an elaborate bit of coordination between masons and carpenters that would make a modern day GC's head explode. Truly a remarkable bit of craftsmanship. There was no way we could get our hands on timbers to replace it or take the brick down and rebuild it as it was, so we opted for a steel frame clad with wood to accept slate.

 

[bridgebuster]

Thanks for the info phamENG.